Quantum Dot Display Science and Technology E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Serie: Wiley Series in Display Technology
- Sprache: Englisch
COMPREHENSIVE REFERENCE PRESENTING ALL ASPECTS OF QUANTUM DOT-BASED DISPLAY TECHNOLOGIES IN FOUR PARTS, SUPPORTED WITH PEDAGOGICAL FEATURES
Quantum Dot Display Science and Technology presents all aspects of quantum dot (QD) based display technologies, divided into four general topic areas: the basic science of quantum dots, QD photoluminescent technologies, QD electroluminescent technologies, and other display related QD technologies. Composed of 14 chapters, this book includes a list of pedagogical features such as tables, illustrations, process flow charts, and more to provide active learning for the reader. This book also includes information on future quantum dot displays and the major milestones in the field.
Quantum Dot Display Science and Technology discusses topics including:
- The basic physics and photophysics of QD, explaining why QD can offer better color and higher brightness
- QD material systems and compositional families as well as principles and practices of QD synthesis
- Quantum dot enhancement film and quantum dot color conversion for LCDs, OLEDs, and μLEDs
- Quantum dot electroluminescent displays and QD-LED panel processes based on ink-jet printing and lithography
- QD for lighting and photodetector applications
- Future outlook for QD displays
Published in partnership with the Society for Information Display (SID), Quantum Dot Display Science and Technology is the perfect resource for updated information on quantum dots and their applications for professionals working in displays, consumer electronics, and product design and development.
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Veröffentlichungsjahr: 2025
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Table of Contents
Cover
Table of Contents
Wiley – SID Series in Display Technology
Title Page
Copyright
Series Editor’s Foreword
About the Editors
Preface
Acknowledgments
Chapter 1: Physics and Photophysics of Quantum Dots for Display Applications
1.1 Introduction
1.2 Quantum Confinement and Band Structure
1.3 Absorption Spectrum
1.4 Charge Carrier Dynamics
1.5 Surface Passivation and Heterostructure Band Alignment
1.6 Emission Intermittency (Blinking) and Stability
1.7 Emission Linewidth
1.8 Dimensionality Effects
1.9 Collective Emission
1.10 Summary and Outlook
References
Chapter 2: Quantum Dot Material Systems, Compositional Families
2.1 Introduction
2.2 II–VI Semiconductor QDs
2.3 III–V Semiconductor QDs: Overview and Properties
2.4 More Recent Families of QDs
2.5 Summary and Outlook
References
Chapter 3: Principles and Practices for Quantum Dots Synthesis
3.1 Introduction
3.2 Principles of Colloidal Quantum Dot Synthesis
3.3 Practices of Colloidal Quantum Dot Synthesis
3.4 Summary and Outlook
References
Chapter 4: Quantum Dot Enhancement Film
4.1 Introduction
4.2 Understanding Color for Displays
4.3 Color in the Modern Era – Defining the Ultimate Visual Experience
4.4 Quantum Dots for QDEF Applications
4.5 Quantum Dot Enhancement Film
4.6 Barrierless Quantum Dot Enhancement Film
4.7 Quantum Dot Diffuser Plate
4.8 Summary and Outlook
References
Chapter 5: Quantum Dot Color Conversion for Liquid Crystal Display
5.1 Introduction
5.2 Thin-film Transistor Liquid Crystal Display
5.3 Quantum Dot Color Conversion for Liquid Crystal Display
5.4 Summary and Prospects
References
Chapter 6: Quantum Dot (QD) Color Conversion for QD-Organic Light-Emitting Diode
6.1 Introduction to Quantum Dot-Organic Light-emitting Diode
6.2 Color Conversion Materials
6.3 Color Conversion Architecture
6.4 Inkjet Printing of CCM
6.5 Conclusion and Future Work
References
Chapter 7: Quantum Dots for Augmented Reality
7.1 Why Quantum Dots for Augmented Reality?
7.2 Augmented Reality Glasses: The Need for High-efficiency Small Emitters
7.3 QD Color Conversion Performance and Reliability Requirements
7.4 Summary and Outlook
References
Chapter 8: CdSe-based Quantum Dot Light-emitting Diodes
8.1 Overview of Quantum Dot Light-emitting Diode Development
8.2 Functional Layers
8.3 Aging Mechanism
8.4 Summary and Outlook
References
Chapter 9: Quantum Dot Light-emitting Device Materials, Device Physics, and Fabrication: Cadmium-free
9.1 Introduction
9.2 Survey of Materials
9.3 Surface Chemistry
9.4 Device Physics and Fabrication
9.5 Patterning for Display Fabrication
9.6 Summary and Outlook
References
Chapter 10: Quantum Dot Light-emitting Diode Panel Process: Inkjet Printing
10.1 Inkjet Printing Technology for QD Patterning in Full-color Displays
10.2 Ink Formulation for Inkjet-Printed QD-LED Displays
10.3 Inkjet Printing Processes and Device Performance of QD-LED Display Panels
10.4 Current Challenges in Inkjet Printing for QD-LED Display and Future Outlook
10.5 Summary and Outlook
References
Chapter 11: Photolithographic Patterning Techniques for Quantum Dot Light-emitting Diodes
11.1 Introduction
11.2 Photolithography Technology
11.3 Indirect Photoresist-assisted Photolithographic Patterning of Quantum Dots
11.4 Direct Photoresist-free Photolithographic Patterning of Quantum Dots
11.5 Industrial Progress
11.6 Summary and Outlook
References
Chapter 12: Quantum Dots in Light-emitting Diodes for General Lighting
12.1 Benefits of Quantum Dots for Illumination
12.2 Illumination Landscape: The Need for Narrow Emitters
12.3 SSL Devices and Solution Development
12.4 QD Performance and Reliability Requirements
12.5 Summary and Outlook
References
Chapter 13: Quantum Dot Photodetector Technology
13.1 Introduction to Sensing with Quantum Dots
13.2 Figures of Merit for QD Sensors
13.3 QD Photodetector Materials and Devices
13.4 Conclusion and Outlook
References
Chapter 14: Future of Quantum Dots in Displays and Beyond
14.1 Introduction
14.2 Implementation of QDs Past, Present, and Future
14.3 QD Materials
14.4 Optical Properties
14.5 Regulatory
14.6 Non-display Applications
14.7 Summary
References
Index
End User License Agreement
List of Illustrations
Chapter 1
Figure 1.1 (a) Quantum confinement effect in quantum dots (QDs). The electronic...
Figure 1.2 (a) Tunneling I–V curve of an InAs quantum dot (QD). The QD is linke...
Figure 1.3 (a) Absorption and fluorescence spectra (top and bottom panels, resp...
Figure 1.4 Schematic of charge carrier dynamics in quantum dots (QDs). (a) Phot...
Figure 1.5 (a) Schematic of the possible band alignments in a heterojunction of...
Figure 1.6 (a) Schematic of a typical setup for single-particle spectroscopy. A...
Figure 1.7 (a) Fluorescence intensity fluctuation time-trace of CdSe/CdS quantu...
Figure 1.8 (a) Spectral fluctuations over time caused by the quantum Stark effe...
Figure 1.9 (a) The shape-dependent quantum confinement effect showcasing the si...
Figure 1.10 (a) Absorption and fluorescence spectra (black and green, respective...
Chapter 2
Figure 2.1 Spectral range of emission for widely used quantum dots compositions...
Figure 2.2 Illustration of band gap engineering as a function of the core and s...
Figure 2.3 (a) Variations in photoluminescence (PL) wavelength, quantum yield, ...
Figure 2.4 (a) Schematic diagram of the Br passivation of the ZnS shell surface. (b) Photol...
Figure 2.5 (a) A schematic representation of the InP surface structure before and after the...
Figure 2.6 Summary of the three distinct shell growth strategies: (a) single-sh...
Figure 2.7 (a) Photographs of Zn–Ag–In–S quantum dots (QDs) of different particle sizes ...
Figure 2.8 Three-dimensional polymorphs of CsPbX
3
in the order of decreasing sy...
Figure 2.9 Comparison of the electronic structures of defect-intolerant semicon...
Figure 2.10 (a) Scheme showing the hot-injection method for the synthesis of col...
Figure 2.11 (a) Reaction path in the TOPO-assisted synthesis of CsPbBr
3
quantum ...
Chapter 3
Figure 3.1 (a) Quantum confinement effect. Comparison of bulk and size-dependen...
Figure 3.2 (a) A schematic depicting the general concept of precursor (ionic mo...
Figure 3.3 (a) Schematics of type-I, type-II, and reverse type-I bandgap alignm...
Figure 3.4 (a) LaMer plot for the synthesis of monodisperse particles describin...
Figure 3.5 (a) UV-vis absorption and photoluminescence (PL) spectra of CdZnTe q...
Figure 3.6 (a) Temporal evolution photoluminescence (PL) spectra of size- and c...
Figure 3.7 (a) Transmission electron micrograph (TEM) image of CdSe nanocrystal...
Figure 3.8 Schematics of colloidal quantum dot (QD) synthesis by (a) flask-base...
Figure 3.9 (a) and (d) Schematics of hot-injection and heating-up synthesis. (I...
Figure 3.10 (a) Time-dependent temperature and power profile under microwave hea...
Figure 3.11 (a) Schematic of seed-assisted nanocrystal (NC) synthesis. (b) Plot ...
Figure 3.12 (a) Schematic of Zn-doped (alloyed) InP core and lattice-matched InZ...
Figure 3.13 (a) Schematic of synthesis procedure for InP/ZnS C/S quantum dots (Q...
Figure 3.14 (a) Top: Description of quantum dots (QDs) treated with MX
n
ligands....
Figure 3.15 (a) Lattice structure of I–III–VI quantum dots (QDs) (chalcopyrite, ...
Chapter 4
Figure 4.1 Diagram of eye photosensitivity showing photoreceptor absorbency for...
Figure 4.2 Chromaticity gamut comparison showing the original 1953 NTSC broadca...
Figure 4.3 Schematic showing how colors are generated from a phosphor-coated wh...
Figure 4.4 Ultimate visual experience, diagrammed.
Figure 4.5 Pointer’s gamut, NTSC 1953, and BT.2020 plotted in CIE 1931.
Figure 4.6 Dolby study on contrast and high dynamic range showing user preferen...
Figure 4.7 Ultimate visual experience and luminance dynamic range.
Figure 4.8 (a) Spectra at display level for a TV that can achieve 98% DCI-P3 co...
Figure 4.9 (a) Spectra at display level for a display that can achieve 93% Rec....
Figure 4.10 Glass capsular tube quantum dot implementation for edge-lit LCDs.
Figure 4.11 Schematic of quantum dot enhancement film construction.
Figure 4.12 Schematic of implementation of a liquid crystal display with quantum...
Figure 4.13 Schematic of barrier film structure.
Figure 4.14 Schematic of commonly used commercial barrier film for quantum dot e...
Figure 4.15 Schematic of co-lamination approach for quantum dot enhancement film...
Figure 4.16 Flowchart of the quantum dot enhancement film fabrication process.
Figure 4.17 Comparing liquid crystal display backlight implementations from edge...
Figure 4.18 EU Ecodesign’s required “cadmium-free” label for all displays with l...
Figure 4.19 Schematic of quantum dot (QD) structure and degradation mechanism of...
Figure 4.20 Flux stability of air-stable quantum dot at 80 °C.
Figure 4.21 Regular quantum dot enhancement film (QDEF) versus barrierless QDEF....
Figure 4.22 Stability of extruded film based on the air-stable quantum dot devel...
Chapter 5
Figure 5.1 The 115-inch product with quantum dot (QD) backlight from TCL [4].
Figure 5.2 (a) Sensitivity of the human eye and (b) CIE 1976 color-matching fun...
Figure 5.3 The spectrum of different backlights (BL). (a) YAG BL; (b) K
2
SiF
6
BL...
Figure 5.4 The basic structure of thin-film transistor liquid crystal display....
Figure 5.5 Mechanisms of thin-film transistor liquid crystal display incorporat...
Figure 5.6 The color gamut of different displays.
Figure 5.7 (a) Quantum dot (QD) backlight and (b) QD-based color filter display...
Figure 5.8 Three different encapsulation architectures of quantum dot backlight...
Figure 5.9 A typical structure of a quantum dot color conversion film.
Figure 5.10 Schematic illustration of color filter lithography process.
Figure 5.11 A schematic illustration of two patterning methods. (a) Negative lit...
Figure 5.12 A schematic illustration of architectures for quantum dot-based colo...
Figure 5.13 A schematic illustration of color crosstalk of liquid crystal displa...
Figure 5.14 A schematic illustration of light collimation for the architecture s...
Figure 5.15 Stokes shift: absorbance and photoluminescence spectra of green and ...
Figure 5.16 (a) Traditional structure with quantum dot (QD)-based color filter (...
Figure 5.17 Colors of quantum dot (QD) excited by blue light with or without (a)...
Figure 5.18 Process flow of the quantum dot-based color filter.
Figure 5.19 (a) A schematic illustration of architecture for nanoimprinted-metal...
Figure 5.20 The process flow of coated dichroic polarizers.
Figure 5.21 (a) Angular dependence of transmittance of a conventional liquid cry...
Figure 5.22 Simulated angular dependence of contrast ratio for liquid crystal di...
Figure 5.23 Schematic illustration of a quantum dot-based color filter organic l...
Chapter 6
Figure 6.1 Simplified configuration of commercialized displays.
Figure 6.2 Schematic picture of color conversion in quantum dot-organic light-e...
Figure 6.3 Blue electroluminescence spectrum, absorption (dash line), and photo...
Figure 6.4 First valley minimum change in absorption spectrum and spectral matc...
Figure 6.5 (a) Scatterer concentration effect on external quantum efficiency of...
Figure 6.6 External quantum efficiency change of quantum dot color conversion m...
Figure 6.7 External quantum efficiency change of quantum dot color conversion m...
Figure 6.8 (a) Bank formation process. Surface energy effect on (b) ink-pining ...
Figure 6.9 (a) Color-filter effect on emission spectrum, comparison of (b) colo...
Figure 6.10 Schematic picture of recycling of (a) leakage blue light and (b) emi...
Figure 6.11 (a) Types of reflection and (b) schematic picture of reflection in q...
Figure 6.12 Methods of minimization of a reflection. (a) Gradual index matching ...
Figure 6.13 Drop volume as a function of (a) driving voltage, (b) frequency, and...
Figure 6.14 (a) Viscosity change with quantum dot (QD) concentration, (b) viscos...
Figure 6.15 Complex rheology parameter , , and at 45 °C.
Figure 6.16 Uniformity control with (a) nozzle mixing and (b) drop location adju...
Figure 6.17 Types of failure: (a) nozzle wetting and (b) nozzle clogging.
Chapter 7
Figure 7.1 Schematic illustration of the optical combiner system and the desire...
Figure 7.2 Various optical combiner solutions for augmented reality glass [5].
Figure 7.3 ARG side view showing display engine location and size constraints.
Figure 7.4 LCoS based display engine schematic showing PBS and optics.
Figure 7.5 DMD system [8].
Figure 7.6 DMD pixel element.
Figure 7.7 Etendue as a function of pixel size for DMD based display projectors...
Figure 7.8 Three-panel μLED display engine [10] versus single (monolithic RGB) ...
Figure 7.9 Options for monolithic microLED display panel fabrication.
Figure 7.10 GaN nanowire diameter effect on emission wavelength.
Figure 7.11 Method of microLED transfer.
Figure 7.12 QD conversion layer using blue pump source microLEDs.
Figure 7.13 QD layer reabsorption illustration.
Chapter 8
Figure 8.1 (a) Schematic picture showing the excitation mechanism of quantum do...
Figure 8.2 Different quantum dot (QD) structures in high-performance QD-LED dev...
Figure 8.3 The multiple roles of surface ligands in determining the properties ...
Figure 8.4 Electron transfer from quantum dots to the deep tail states of polym...
Figure 8.5 Modification of ZnO NP surface properties. (a) Ionic metal doping st...
Figure 8.6 (a) Schematic of the transformation from the bipolar devices to the ...
Figure 8.7 (a) Ligand exchange from cadmium-carboxylates (with a small amount of negatively...
Figure 8.8 (a) Comparison of electroabsorption (EA) characterization of red and blue QD-LED...
Figure 8.9 (a) Device structure and device performance under different storage days. The XP...
Figure 8.10 The world’s first 14″ 2.8K inkjet-printed QD-LEDs laptop display de...
Chapter 9
Figure 9.1 Semiconductor materials for cadmium-free QDs and the ranges of emiss...
Figure 9.2 Band diagrams of core/shell compositions for red CdSe and red, green...
Figure 9.3 (a) Optimization of shell thickness of red InP QDs toward optimum de...
Figure 9.4 Schematic illustration (top) and corresponding TEM images (bottom) o...
Figure 9.5 Ligand exchange from oleic acid to hexanoic acid on red InP/ZnSe/ZnS...
Figure 9.6 Schemes showing (a) sequential ZnCl
2
ligand exchanges in solution an...
Figure 9.7 Energy level diagram of (a) conventional structure and (b) inverted ...
Figure 9.8 (a) Energy band diagram of (left) hole-excess and (right) electron-e...
Figure 9.9 Schematics of optical patterning processes.
Figure 9.10 Photograph of a 12.3″ active-matrix QD-LED display employing Cd-free...
Figure 9.11 History of development of EQE (a, c, e) and T50 lifetime at 100 cd m...
Chapter 10
Figure 10.1 Schematic illustration of thermal and piezoelectric drop-on-demand p...
Figure 10.2 Structure of core/shell quantum dot (QD) with surface ligands and th...
Figure 10.3 Chemical structure of representative organic charge transport materi...
Figure 10.4 Comparison of a normal and an inverted quantum dot light-emitting di...
Figure 10.5 Device structure and operation mechanism of a quantum dot (QD) light...
Figure 10.6 Increase in the efficiency of quantum dot light-emitting diodes (QD-...
Figure 10.7 Piezoelectric transducer (PZT) displacement and sequence of ink drop...
Figure 10.8 (a) Schematic illustration of drop displacement onto the bank, (b) d...
Figure 10.9 Methods for controlling and calibrating drop variation in inkjet pri...
Figure 10.10 Optical images of ink volume deposited on confined pixel substrates ...
Figure 10.11 Examples of mura observed in all areas of 12.5-inch all-inkjet-print...
Figure 10.12 (a) Schematic illustration of the drying process of droplet in the c...
Figure 10.13 Image of 18.2″ all-inkjet-printed quantum dot light-emitting diode ...
Figure 10.14 Recent progress in the performance of all-inkjet-printed quantum dot...
Figure 10.15 Inkjet-printed quantum dot light-emitting diode display panels repor...
Figure 10.16 Comparison of display technologies: LCD, OLED, QD-LED, and micro-LED...
Figure 10.17 Quantum dot light-emitting diode display value chain including panel...
Figure 10.18 TV display forecast by technology by year.
Chapter 11
Figure 11.1 Basics of lithography in semiconductor manufacturing. (a) Schematic ...
Figure 11.2 Schematics of the process flow of patterning quantum dots (QDs) usin...
Figure 11.3 Schematics of the patterning of the quantum dots (QDs) film using ph...
Figure 11.4 Schematics of the patterning of quantum dots (QDs) film using photor...
Figure 11.5 Direct photoresist-free photolithographic patterning of the quantum...
Figure 11.6 Direct photoresist-free photolithographic patterning of QDs by cross...
Figure 11.7 Schematic of the classification of surface ligands in the case of a ...
Figure 11.8 Direct photolithographic patterning of QDs through the stripping of...
Figure 11.9 Direct photolithographic patterning of QDs through ligand exchange...
Figure 11.10 Photolithographic patterning strategies for maintaining the photoph...
Figure 11.11 Quantum dot light-emitting diode prototypes fabricated using lithogr...
Chapter 12
Figure 12.1 (a) Calculated blackbody emission spectra for various temperature em...
Figure 12.2 Direct emission from separate blue, green, and red LEDs: from ams OS...
Figure 12.3 Cartoon depicting a light-emitting diode package filled with both gr...
Figure 12.4 Test color samples used in color rending index calculations.
Figure 12.5 Truncated blackbody radiation along with a light-emitting diode spec...
Figure 12.6 Color Rendering Index (CRI) Ra and R9 values for various temperature...
Figure 12.7 Luminous efficacy of radiation values for various temperature blackb...
Figure 12.8 Luminous efficacy of radiation plotted as a function of correlated c...
Figure 12.9 Cartoon representation of a quantum dot with multiple shell layers e...
Figure 12.10 Quantum dot-based light-emitting diode for illumination: OSCONIQ
®
E ...
Figure 12.11 Emission spectra for standard downconversion materials typically use...
Figure 12.12 High-temperature operating lifetime stability data of on-chip quantu...
Figure 12.13 Modeled emission spectra comprised of narrow emission peaks. The col...
Chapter 13
Figure 13.1 Quantum dot (QD) image sensor cross section: (a) view through four p...
Figure 13.2 Solar spectrum at sea level (AM1.5G) with overlaid external quantum ...
Figure 13.3 Ideal and “realistic” photodiode JV curves.
Figure 13.4 External quantum efficiency versus wavelength (a) and versus bias (b...
Figure 13.5 Effect of scaling the pixel pitch from 5 to : better resolution...
Figure 13.6 Examples of images acquired with quantum dot image sensors: SWIR Vis...
Figure 13.7 Cross-section SEM images of a QDPD stack integrated on top of CMOS R...
Chapter 14
Figure 14.1 Implementation of quantum dot technology in multiple ways for displa...
Figure 14.2 Left: External quantum efficiency as a function of LED size for GaN ...
Figure 14.3 Quantum dot color converted microLED approach with a UV microLED com...
Figure 14.4 Photo of BOE’s quantum dot light-emitting diode display demonstratio...
Figure 14.5 Improvements in perovskite quantum dot light-emitting diode devices ...
Figure 14.6 Perovskite tunability throughout the visible spectrum with narrow FW...
Figure 14.7 Example properties of AIGS quantum dots that could be used in displa...
Figure 14.8 Photo of nitride quantum dots and their absorption/emission spectra ...
Figure 14.9 Approximate mass of quantum dots used in four different integration ...
Figure 14.10 Examples of anisotropic quantum dot systems [19].
Figure 14.11 Example of modeled display system demonstrating advantages of using ...
Figure 14.12 Temperature and light flux of some common quantum dot implementation...
Figure 14.13 Extruded quantum dot materials and xQDEF part.
Figure 14.14 Different methods of encapsulating quantum dots with barrier shells ...
Figure 14.15 Summary from multiple conference presentations and published sources...
Figure 14.16 Comparison of measured commercial parts based on CdSe quantum dots a...
Figure 14.17 Comparison of desirability vs. narrowing linewidth and its impact on...
Figure 14.18 Left: Representative InP absorption (dotted line) and emission (soli...
Figure 14.19 Spectral breakdown of LEDs, quantum dot part with a photo of the mea...
Figure 14.20 Example spectra and color gamut for a 4-primary display [41].
Figure 14.21 Three possible uses of CIS quantum dots for spectral engineering. Gr...
Figure 14.22 Champion conversion efficiencies for research solar cells [45].
List of Tables
Chapter 2
Table 2.1 Basic physical properties of III–V semiconductors.
a
Table 2.2 Properties of commonly used (P) precursors and their reaction with I...
Table 2.3 Basic properties of InP and related shell materials, all of which cr...
Table 2.4 Representative data for InP QD-based core–shell structures and their...
Table 2.5 Different types of highly luminescent InAs QD-based core–shell struc...
Table 2.6 Phase transition in CsPbX
3
bulk perovskites.
Chapter 3
Table 3.1 Bottom-up approaches for making colloidal quantum dots (CQDs).
Chapter 4
Table 4.1 Typical optical properties of commercial quantum dots for a liquid c...
Table 4.2 Permeability coefficient of oxygen and water vapor for glass an...
Table 4.3 Change of optical properties of the air-stable QDs developed by Nano...
Chapter 5
Table 5.1 The functions of quantum dot (QD)-based color filter composition in ...
Table 5.2 The process difference between lithography and inkjet printing (IJP)...
Table 5.3 Comparison of light efficiency of quantum dots (QDs) in different ap...
Chapter 6
Table 6.1 Molar absorption parameter of green quantum dots at 450 nm wavelengt...
Chapter 7
Table 7.1 Typical efficiency of common waveguides.
Chapter 10
Table 10.1 The key differences between drop-on-demand (DOD) and continuous inkj...
Table 10.2 Commercially available inkjet printheads [6–11].
Table 10.3 Representative inorganic charge-transporting materials.
Table 10.4 Device performance of representative Cd-free quantum dot light-emitt...
Chapter 12
Table 12.1 Photon conversion rates by color for both phosphor-downconverted sys...
Table 12.2 CRI Ra and R9 requirements for typical classes of solid-state lighti...
Table 12.3 Color Rendering Index (CRI) Ra and R9 requirements for typical class...
Chapter 13
Table 13.1 Typical figures of merit reported for materials/films.
Table 13.2 Typical figures of merit reported for photodiodes.
Table 13.3 Typical figures of merit reported for image sensors.
Table 13.4 Typical reliability tests used for photodetectors and imagers.
Table 13.5 Comparison of features characteristic for different quantum dot type...
Chapter 14
Table 14.1 Comparison of the properties of various quantum dot material systems...
Table 14.2 Impact of RoHS Exemption 39 changes in 2024 to major quantum dot tec...
Guide
Cover
Table of Contents
Wiley – SID Series in Display Technology
Title Page
Copyright
Series Editor’s Foreword
About the Editors
Preface
Acknowledgments
Begin Reading
Index
End User License Agreement
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Wiley – SID Series in Display Technology
Series Editor: Susan K. Jones
Paul Alivisatos, Eunjoo Jang, Ruiqing Ma (Eds.)
Quantum Dot Display Science and Technology
2025
Phil Green (Ed)
Fundamentals and Applications of Colour Engineering
Darran R. Cairns, Dirk J. Broer, Gregory P. Crawford (Eds.)
Flexible Flat Panel Displays
2023
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E-Paper Displays
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Amorphous Oxide Semiconductors: IGZO and Related Materials for Display and Memory
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Liquid Crystal Displays: Addressing Schemes and Electro-Optical Effects, 3ed
2022
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Introduction to Flat Panel Displays, 2ed
2020
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Flat Panel Display Manufacturing
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OLED Displays: Fundamentals and Applications 2ed
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Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Application to Displays
2017
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Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Application to LSI
Noboru Kimizuka, Shunpei Yamazaki
Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Fundamentals
2016
Dmitry A. Yakovlev, Vladimir G. Chigrinov, Hoi-Sing Kwok
Modeling and Optimization of LCD Optical Performance
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Interactive Displays
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Addressing Techniques of Liquid Crystal Displays
Deng-Ke Yang, Shin-Tson Wu
Fundamentals of Liquid Crystal Devices
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Illumination, Color and Imaging: Evaluation and Optimization of Visual Displays
2012
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Liquid Crystal Displays: Fundamental Physics and Technology
2011
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Transflective Liquid Crystal Displays
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Photoalignment of Liquid Crystalline Materials: Physics and Applications
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Mobile Displays: Technology and Applications
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2005
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Colour Engineering: Achieving Device Independent Colour
2002
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Display Systems: Design and Applications
1997
Quantum Dot Display Science and Technology
Edited by
Paul Alivisatos
University of Chicago
Eunjoo Jang
Sungkyunkwan University
Ruiqing Ma
Meta
This edition first published 2025
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Names: Alivisatos, P., editor. | Jang, Eunjoo, (Professor), editor. | Ma, Ruiqing, editor.
Title: Quantum dot display science and technology / edited by Paul Alivisatos, Eunjoo Jang, Ruiqing Ma.
Description: Hoboken, NJ : Wiley, 2025. | Series: Wiley series in display technology | Includes bibliographical references and index.
Identifiers: LCCN 2025004043 (print) | LCCN 2025004044 (ebook) | ISBN 9781394181858 (hardback) | ISBN 9781394181865 (adobe pdf) | ISBN 9781394181872 (ebook) | ISBN 9781394181889 (obook)
Subjects: LCSH: Quantum dots. | Information display systems.
Classification: LCC TK7874.88 .Q3625 2025 (print) | LCC TK7874.88 (ebook) | DDC 621.3815/2–dc23/eng/20250304
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Series Editor’s Foreword
Display technology makes advances through many innovations, which cumulatively over several decades have brought us from simple (and rather dull) digital watch displays to today’s large and vibrant flat panel televisions, mobile devices and professional applications. For the most part, these innovations are modest in their individual impact on the technology and their contribution to user experience is only incremental. But the adoption of quantum dot technologies into consumer and professional displays is clearly one of those less common changes which breaks this pattern of incremental change and has fundamentally altered the landscape of what is possible and expected from modern devices. This makes it a special pleasure to introduce the current volume, as an addition to the SID book series.
The improvement in display performance, which quantum dots make possible, is simple in principle. A wide color gamut can only be obtained when the primary light emission is placed at optimized wavelengths in the red, green, and blue regions of the spectrum, and – crucially – with a very narrow emission wavelength range. Any attempt to realize such primaries by filtering a broadband emitter is doomed to cause a disastrous loss of power efficiency. Quantum dots, by contrast, provide a route to exactly the required narrow emission properties, and moreover the wavelength emitted by a single material can be tuned by optimizing the particle size. In contrast to this conceptual simplicity, the tasks of achieving high efficiency, long lifetime, repeatable batch performance, and economical processing have presented formidable challenges. The editors of this book are distinguished pioneers in the field of quantum dot technology, who have assembled an outstanding collection of authors who provide a comprehensive and authoritative overview of the entire field, including the fundamental physics of quantum dots, the materials families which are exploited, the synthesis of the materials, their processing and different modes of use in OLED and LCD panels as well as other applications such as sensing and lighting. Key issues such as passivation, optimization of charge transport, avoidance of photo bleaching, role of surface ligands, and the influence of government regulations are covered in the appropriate sections. Scientists, engineers, and students in a broad range of display development and applications will find an invaluable resource here.
On a personal level, I expect this to be the last Series Editor’s Foreword that I contribute, before finally stepping back from the role. It has been particularly rewarding in my time as series editor, to see the outstanding advances made by display scientists and engineers reflected in the pages of series volumes. This volume perfectly exemplifies the place of the series in bringing the most significant developments to the display community and gives me confidence that the next decades will continue to deliver exciting and inspiring new technologies, which will continue to accelerate display use in all our lives.
Ian Sage
Great Malvern, UK
About the Editors
Paul Alivisatos is the 14th president of the University of Chicago, where he also holds a faculty appointment as the John D. MacArthur Distinguished Service Professor in the Department of Chemistry, the Pritzker School of Molecular Engineering, and the College. Previously, he held professorships from 1988 to 2021 in the Departments of Chemistry and Materials Science at UC Berkeley and served in several administrative roles, including Executive Vice Chancellor and Provost (EVCP). He was the founding Director of the Kavli Energy Nanoscience Institute, and from 2009 to 2016, he served as Director of the Lawrence Berkeley National Laboratory. Alivisatos received his Bachelor’s degree in Chemistry in 1981 from the University of Chicago and his PhD in Chemistry from Berkeley in 1986. He has made pioneering research breakthroughs in nanomaterials and contributed to the fundamental physical chemistry of nanocrystals. He has been recognized for his accomplishments with more than 25 awards, including the National Medal of Science. He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society.
Eunjoo Jang has been a professor at Sungkyunkwan University since 2024. She was a Fellow at Samsung Electronics from 2017 to 2023. She received her PhD in 1998 from the Chemical Engineering Department at Pohang University of Science and Technology (POSTECH) and completed her postdoctoral research at the University of Ottawa in 1999. She joined Samsung in 2000 and has been developing various QD materials and optoelectronic devices since 2023. She led many projects on QD development, successfully scaled up InP-based QDs (Cd-free), and commercialized Samsung’s QLED TVs using internally developed QDs since 2015. She has issued more than 250 US patents and published more than 50 peer-reviewed articles on QD technology. She is a member of the National Academy of Engineering of Korea, the Materials Research Society, the Society for Information Display, and the Korean Information Display Society.
Ruiqing Ma is a Fellow of the Society for Information Display (SID). He received his PhD in Chemical Physics in 2000 from the Liquid Crystal Institute at Kent State University. Before joining Meta in 2022, he was the Senior Director of R&D at Nanosys from 2017 to 2022, leading QD device research with a focus on cadmium-free QDEL technology. He also worked for Universal Display Corp. (2007–2017), Honeywell (2005–2007), and Corning Inc. (1999–2005). His research interests include quantum dot photoluminescent and electroluminescent technologies, OLED device physics and optics, liquid crystal display optics, flexible displays, and ultra-high-resolution displays for AR/VR applications. He has over 100 issued US patents and more than 80 publications.
Preface
The idea to start this book project was born out of a pressing need for a comprehensive resource on quantum dots (QDs) for display applications. This need arises from the fact that QD display development efforts are often isolated from each other due to the diverse range of applications and requirements. Unlike the more linear evolution of technologies like Liquid Crystal Displays (LCDs) and Organic Light-Emitting Diodes (OLEDs), QDs have carved a niche as a supporting technology, offering superior color quality at a low cost. This is achieved through the narrow emission spectrum of QDs and the ability to fine-tune colors by altering QD sizes, all while leveraging cost-effective solution processes.
The first quantum dot display products were developed in the search for a technology that could improve the color performance of LCDs to compete against the emerging OLED technology. In 2013, the same year that OLED smartphone displays reached 441 ppi and the first 55” OLED TVs were launched, Sony and QD Vision commercialized the first QD LCD TVs with “Color IQ” technology, marking the beginning of the commercialization of QD displays. That same year, 3M and Nanosys introduced the first Quantum Dot Enhanced Film (QDEF) in Amazon’s Kindle Fire HDX 7-inch model. The QDEF approach, which later became the industry standard, integrates a QD film with a blue light-emitting diode (LED) backlight, achieving vibrant, saturated colors even at high luminance. In 2022, the first two TVs powered by QD-OLED panels were introduced: the Sony A95K OLED and the Samsung S95B OLED. These panels replaced low-efficient color filters with QDs, improving OLED efficiency and color, especially at high brightness.
Today, QD displays are ubiquitous in the form of QDEF-based LCDs and QD-OLED-based OLED TVs, although few consumers are aware of their existence. With QDs’ success in helping improve LCDs and OLEDs, it is reasonable to expect they will continue to support other technologies, such as micro-LED for augmented reality (AR) and LED for solid-state lighting. Eventually, QDs could grow out of their supporting role and become leaders in the form of the quantum dot light-emitting diode.
In each of these cases, the development needs for QD properties, device configurations, and fabrication processes differ. Given the diverse range of applications and requirements for QDs, we believe there is a significant benefit in bringing together researchers from various fields to share their results and learnings. By doing so, we can stimulate new ideas, collaborations, and innovations in the field of QD displays.
As we delved deeper into this project, we became even more convinced of the importance of this work. We hope this book will serve as a valuable resource for anyone interested in QD displays, ultimately advancing the field by deepening our understanding and broadening the applications of this exciting technology.
Acknowledgments
In compiling this book, we have been fortunate to receive state-of-art technical contributions from renowned researchers around the world. This book could not have been completed without their contributions. We are deeply indebted to the following researchers who took the time to make this project a reality:
Einav Scharf, Uri Banin, Sudarsan Tamang, Karl David Wegner, Peter Reiss, Derrick Allan Taylor, Justice Agbeshie Teku, Jong-Soo Lee, ZhongSheng Luo, Jeff Yurek, Zhifu Li, Ji Li, Yanan Wang, Hyeokjin Lee, Gakseok Lee, Taehyung Hwang, Keunchan Oh, Jason Hartlove, Yiran Yan, Longjia Wu.Weiran Cao, Xiaolin Yan, Igor Coropceanu, Heeyoung Jung, Christian Ippen, Dong Jin Kang, Changhee Lee, Yanzhao Li, Shaoyong Lu, Zhuo Chen, Zhuo Li, Xiangbing Fan, Peng Bai, Haoyu Yang, Dong Li, Benjamin Mangum, Juanita Kurtin, Paweł Malinowski, Itai Lieberman, Jonny Steckel, and Peter Palomaki.
We would like to thank Dr. Changhee Lee, who assisted with the planning of the book project in the early stage, and the strong support from the technical program committee of the Society for Information Display (SID).
We would like to thank Kavipriya, Becky, Veena, Devi, Anju, and Sandra from Wiley for their constant support and timely inputs regarding the completion of various phases of this book. We also thank Wiley for their assistance in creating the index for the book. We are thankful to our respective institutions for providing us the opportunity to carry out this work and for providing us with an intellectually stimulating environment.
Finally, we would like to acknowledge the unwavering support by our colleagues, friends, and family members who are responsible for this book in more ways than even they know. We dedicate this book to them.
Paul Alivisatos, Eunjoo Jang, and Ruiqing Ma
Chapter 1Physics and Photophysics of Quantum Dots for Display Applications
Einav Scharf, Uri Banin
Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, Israel
1.1 Introduction
Semiconductor quantum dots (QDs) are nanocrystals composed of hundreds to thousands of atoms, forming a lattice of nanometric size. They exhibit highly bright and stable emission, with color tunable via size, composition, and shape, and can achieve fluorescence quantum efficiency approaching unity [1]. These qualities along with their narrow emission linewidth make them prominent building blocks for display applications. The unique characteristics of QDs already enhance the properties of existing display technologies, and with further developments, they are bound to penetrate display device technologies even to greater extent. In this chapter, we will review briefly the fundamental principles governing the optoelectronic characteristics of such QDs, serving as a basis for their utility in displays.
1.2 Quantum Confinement and Band Structure
The electronic structure of semiconductor QDs manifests a manifold of fully occupied valence band (VB) states and a manifold of empty conduction band (CB) states, separated by the bandgap. Excitation of the QD, for example, by the absorption of a photon, promotes an electron to the CB, leaving an electron vacancy, a hole, in the VB. This electron–hole pair, termed as an exciton, is bound by Coulomb attraction, granting a typical exciton binding energy and an exciton Bohr radius [2]. The Bohr radius is analogous to the Bohr radius of an electron orbiting the nucleus of a hydrogen atom. However, in the case of the QD, it is influenced by the dielectric environment and the effective mass of the semiconductor electron and hole charge carriers, resulting in an exciton Bohr radius in the nanometric scale. QDs that are smaller than the exciton Bohr radius of the corresponding semiconductor exhibit strong quantum confinement, which leads to discretization of the energy levels and size-dependent electronic and optical properties (Figure 1.1a) [3]. By varying the size of the QD, for suitable semiconductors such as InP or CdSe, its emission color can thus be tuned from blue for the smallest QDs with a diameter smaller than 2 nm, through the entire visible spectrum and to the near-infrared for large QDs with a radius of 10 nm (Figure 1.1b).
Figure 1.1 (a) Quantum confinement effect in quantum dots (QDs). The electronic structure varies with the size of QD. A bulk semiconductor (in gray) presents a fundamental bandgap between the valence band (VB) and conduction band (CB). Upon formation of QDs, the discrete states arise due to the quantum confinement effect and the bandgap increases from large to small QDs. (b) Emission from a series of CdSe QDs with sizes ranging from smaller than 2–6 nm with colors covering the visible spectrum, from blue to red, respectively, demonstrating the quantum confinement effect. (c) Electronic structure of the first two energy levels in the VB and CB.
The QD behavior can be derived by solving the particle-in-a-spherical-box problem, describing the behavior of an electron and a hole in the QD [4]. This involves solving the Schrödinger equation, in its central potential form (the potential depends only on radius):
where the Hamiltonian has separable radial and angular components. The first two terms are of the kinetic energy. is the square of the angular momentum operator, is the potential energy, and is the wave function. This problem resembles the problem of the hydrogen atom considering it being a central potential that depends on radius, and accordingly the solution for the angular part of the wave functions is similar as well. However, the main difference between the derivation of the hydrogen atom and of the QD is in the actual form of the potential energy. In the hydrogen atom, the electron is attracted to the nucleus by the Coulomb potential, whereas in the case of an electron in a QD, the potential inside the spherical box is zero and, for simplification as a first approximation, is infinite outside the box. In both the hydrogen atom and the QD, the potential depends solely on the radial distance and is independent of the angle. Therefore, in both problems, the angular solution is described by spherical harmonics. In QDs, the spherical solution can be described by spherical Bessel functions. Since the solution of the angular equation is the spherical harmonics, the energy levels are defined by four quantum numbers: the principal quantum number n, the angular momentum quantum number , the angular momentum projection quantum number , and the spin quantum number . In contrast to the hydrogen atom, the condition on the relation between the principal and angular momentum quantum numbers is canceled. Accordingly, the energy levels are denoted as for the electron and for the hole states, with denoted in numbers, and using common notation of for , for , for , etc. The first energy levels in the QD are thus , , for the electron (hole) in the CB (VB; Figure 1.1c) [5]. As in the hydrogen atom, the value of is in the range of to , resulting in a degeneracy of . The energy levels under the strong confinement approximation, for QDs that are smaller than the exciton Bohr radius, are described by:
where is the effective mass of the electron or the hole , is the radius of the QD, and is the allowed solutions arising from demanding that the wave function is 0 on the surface of the QD. For the band edge optical transition (), . The strong confinement approximation allows to treat the electron and hole as uncorrelated, neglecting in the first step the Coulomb interaction [6, 7]. Then, the Coulomb term is reintroduced using perturbation theory. This redshifts the bandgap by adding the weak attractive Coulomb interaction term [8], as approximated by:
where is the bulk bandgap energy, and are the electron and hole effective masses, respectively, is the electron charge, and is the dielectric constant.
The optical transitions, which are typically seen in absorption and emission, are dictated by selection rules [6]. The transition probability is proportional to:
where is the wave function of the electron or the hole , and is the transition dipole moment operator.
Under the envelope function approximation, the electron and hole wave functions are separated into the periodic Bloch part and the envelope part (see Eq. 1.5) [9]. Integration of the Bloch part is related to the bulk crystal lattice, approximated to be unaffected by the QD size ( in Eq. 1.5). Integration of the envelope part yields the overlap term for the electron–hole wave functions, and as the eigenstates of a particle-in-a-sphere are orthonormal, we obtain:
where is the Bloch term of the bulk semiconductor and is the envelope function ( or for electron or hole, respectively). is the oscillator strength in the bulk semiconductor and is the Kronecker delta function. Accordingly, the allowed optical transitions are those that conserve the principal and angular momentum quantum numbers of the electron–hole envelope functions of a particle-in-a-sphere (, ) [9, 10].
According to the similarity to degeneracy of the hydrogen atom energy levels, QDs can be referred to as artificial atoms [11]. This property can be probed by scanning tunneling microscopy, where a voltage is applied on a tip hovering above the QD at a distance of ~1 nm, and the tunneling current is measured. Figure 1.2a shows the tunneling I–V curve of an InAs QD [12]. Plotting the tunneling conductance spectrum reveals the density of states (Figure 1.2b). In the positive bias, the CB energy levels are probed, revealing a doublet of the two electrons in the energy level, separated by a charging energy. After a larger separation, a sextet is resolved to be assigned to the six electrons occupying the energy level. In negative bias, the VB states are slightly more convoluted, as the spacing between the energy levels is smaller. The difference between the VB and CB apparent density of states arises from the typically heavier hole, confining the energy levels closer to the band edge, and from the different orbitals constructing the bands. The CB is typically essentially constructed from the empty atomic s orbitals of the corresponding cationic element composing the semiconductor (i.e. In3+ in the case of InAs), whereas the VB is typically constructed from the atomic p orbitals related to the corresponding anionic element (As3− in the case of InAs). At , the bulk VB has a twofold degeneracy of the heavy hole and light hole p3/2 bands and below them the split-off hole p1/2 band (Figure 1.2c) [13]. This leads to a rich and dense level structure in the VB of such QDs.
Figure 1.2 (a) Tunneling I–V curve of an InAs quantum dot (QD). The QD is linked to a gold substrate and the scanning tunneling microscopy (STM) tip scans it from the top (right inset). The left inset presents a 10 × 10 nm2 STM topographic image of the QD. (b) Tunneling conductance spectrum presenting the density of states in the CB (VB) in positive (negative) bias. is the charging energy.
Source: (a, b) Reproduced from [12]/with permission of Springer Nature.
(c) Scheme of the VB structure of the bulk semiconductor InAs at containing three sub-bands arising from the participating atomic p orbitals (heavy hole, hh; light hole, lh; split-off hole, so). is the spin–orbit coupling energy.
Source: Reproduced from [13]/with permission of American Physical Society.
1.3 Absorption Spectrum
The discretization of the energy levels in the QD is apparent also in the absorption of light. QDs can absorb light in a broad range, making them ideal candidates for applications involving photoexcitation. Unlike in semiconductor bulk material, the absorption spectrum exhibits features, owing to the discrete optical transitions between the VB and the CB [5], termed as excitonic transitions. Under the strong confinement regime, the absorption and emission spectra are size-dependent, thus the band edge transition and transition in higher energies shift according to the QD size (Figure 1.3a). The absorption features can be difficult to resolve due to inhomogeneous broadening, originating from the size dispersion of the QDs in the sample (Figure 1.3b, top panel). To overcome this challenge, photoluminescence excitation (PLE) experiments can uncover the homogeneous absorption features of an inhomogeneous sample. The PLE measurement allows selection of a subpopulation within the size dispersion according to a selected emission energy. Then, the excitation wavelength is scanned revealing absorption features with reduced inhomogeneous broadening (Figure 1.3b, bottom panel) [13, 14].
Figure 1.3 (a) Absorption and fluorescence spectra (top and bottom panels, respectively) of a series of quantum dots (QDs) of different sizes.
Source: Reproduced from [41] with permission from American Chemical Society.
(b) Top panel presents the absorption and fluorescence spectra (solid and dashed lines, respectively) of CdSe QDs at 10 K. The arrow pointing downward marks the emission wavelength selected for PLE. Bottom panel shows the measured PLE spectrum.
Source: Reproduced from [13] with permission from American Physical Society.
1.4 Charge Carrier Dynamics
Absorption of a photon in higher energy than the bandgap forms a “hot” exciton in a photoexcitation process. An exciton can also be formed by electrical excitation, where by applying electric bias, electrons fill the CB and are removed from the VB to form holes (Figure 1.4a). The formed “hot” exciton first undergoes nonradiative thermalization process, involving electron–phonon interactions or Auger electron–hole energy transfer (Figure 1.4b). These pathways are in the sub-picosecond to picosecond timescale [15]. Then, the electron and hole occupy the band edge energy levels and can undergo several processes (Figure 1.4c). A radiative pathway involves recombination of the electron–hole pair in a nanosecond to microsecond timescale and results in photon emission. This emission process is essential when considering QDs as building blocks for display. However, two main nonradiative processes are competing with the light emission from the QD. One is trap-assisted relaxation and another is Auger recombination. Dangling bonds on the surface of the QD form energy levels within the bandgap that operate as charge traps, trapping charges and leading to nonradiative relaxation to the VB. The trapping and nonradiative relaxation has a similar timescale as the radiative recombination process [16]. Auger recombination is a multicarrier process, involving energy transfer of the electron–hole recombination to a third charge carrier. This process is highly efficient in the nanoscale confined regime due to the high overlap between charge carriers in close proximity and relaxation of momentum conservation [17]. Therefore, Auger recombination occurs in a timescale of few picoseconds to hundreds of picoseconds, exceeding significantly the typical rates of radiative recombination and thus reducing the fluorescence quantum yield [18]. These nonradiative processes can be detrimental to the emission of the QDs, jeopardizing their potential in display-based devices. However, means to hinder nonradiative processes and even achieve unity quantum yield have been developed, as discussed later.
Figure 1.4 Schematic of charge carrier dynamics in quantum dots (QDs). (a) Photoexcitation or electroexcitation of the QD forms a “hot” electron–hole pair. In electroluminescence, electrons are injected into the CB through an electron transporting layer (ETL) and electrons are extracted from the VB through a hole transporting layer (HTL), leaving holes in the VB. (b) The charges decay to the band edge in a thermalization process. (c) The exciton recombines either radiatively or nonradiatively via trap-assisted recombination or Auger recombination.
Source: Reproduced from [2] with permission from John Wiley & Sons.
1.5 Surface Passivation and Heterostructure Band Alignment
Nonradiative processes highly depend on dangling bonds and defects on the surface of the QD. Accordingly, an increased fluorescence quantum yield is associated with proper passivation of the surface. This can be achieved by molecular ligands that bind to the surface atoms of the QD. Another approach is to tailor the potential with an inorganic heterostructure system, or in other words, by growing a semiconductor shell around the QD core. This can achieve several band alignments, each with a set of properties that can benefit different application types (Figure 1.5a
