Semiconductor Electrochemistry E-Book

Rüdiger Memming

• Herausgeber: Wiley-VCH
• Kategorie: Fachliteratur
• Sprache: Englisch
• Veröffentlichungsjahr: 2015

Seitenzahl: 838

Beschreibung

Providing both an introduction and an up-to-date survey of the entire field, this text captivates the reader with its clear style and inspiring, yet solid presentation. The significantly expanded second edition of this milestone work is supplemented by a completely new chapter on the hot topic of nanoparticles and includes the latest insights into the deposition of dye layers on semiconductor electrodes. In his monograph, the acknowledged expert Professor Memming primarily addresses physical and electrochemists, but materials scientists, physicists, and engineers dealing with semiconductor technology and its applications will also benefit greatly from the contents.

Leseprobe

Contents

Cover

Contents

Series Page

Title Page

Copyright Page

Preface to the Second Edition

Preface

Chapter 1: Principles of Semiconductor Physics

1.1 Crystal Structure

1.2 Energy Levels in Solids

1.3 Optical Properties

1.4 Density of States and Carrier Concentrations

1.5 Carrier Transport Phenomena

1.6 Excitation and Recombination of Charge Carriers

1.7 Fermi Levels under Nonequilibrium Conditions

Chapter 2: Semiconductor Surfaces and Solid–Solid Junctions

2.1 Metal and Semiconductor Surfaces in a Vacuum

2.2 Metal–Semiconductor Contacts (Schottky Junctions)

2.3 p–n Junctions

2.4 Ohmic Contacts

2.5 Photovoltages and Photocurrents

2.6 Surface Recombination

Chapter 3: Electrochemical Systems

3.1 Electrolytes

3.2 Potentials and Thermodynamics of Electrochemical Cells

Chapter 4: Experimental Techniques

4.1 Electrode Preparation

4.2 Current–Voltage Measurements

4.3 Measurements of Surface Recombination and Minority Carrier Injection

4.4 Impedance Measurements

4.5 Surface Conductivity Measurement

4.6 Flash Photolysis Investigations

4.7 Surface Science Techniques

Chapter 5: Solid–Liquid Interface

5.1 Structure of the Interface and Adsorption

5.2 Charge and Potential Distribution at the Interface

5.3 Analysis of the Potential Distribution

5.4 Modification of Semiconductor Surfaces

Chapter 6: Electron Transfer Theories

6.1 The Theory of Marcus

6.2 The Gerischer Model

6.3 Quantum Mechanical Treatments of Electron Transfer Processes

6.4 The Problem of Deriving Rate Constants

6.5 Comparison of Theories

Chapter 7: Charge Transfer Processes at the Semiconductor–Liquid Interface

7.1 Charge Transfer Processes at Metal Electrodes

7.2 Qualitative Description of Current–Potential Curves at Semiconductor Electrodes

7.3 One-step Redox Reactions

7.4 The Quasi-Fermi-Level Concept

7.5 Determination of the Reorganization Energy

7.6 Two-step Redox Processes

7.7 Photoluminescence and Electroluminescence

7.8 Hot Carrier Processes

7.9 Catalysis of Electrode Reactions

Chapter 8: Electrochemical Decomposition of Semiconductors

8.1 Anodic Dissolution Reactions

8.2 Cathodic Decomposition

8.3 Dissolution under Open Circuit Conditions

8.4 Energetics and Thermodynamics of Corrosion

8.5 Competition between Redox Reaction and Anodic Dissolution

8.6 Formation of Porous Semiconductor Surfaces

Chapter 9: Photoreactions at Semiconductor Particles

9.1 Quantum Size Effects

9.2 Charge Transfer Processes at Semiconductor Particles

9.3 Charge Transfer Processes at Quantum Well Electrodes (MQW, SQW)

9.4 Photoelectrochemical Reactions at Nanocrystalline Semiconductor Layers

Chapter 10: Electron Transfer Processes between Excited Molecules and Semiconductor Electrodes

10.1 Energy Levels of Excited Molecules

10.2 Reactions at Semiconductor Electrodes

10.3 Comparison with Reactions at Metal Electrodes

10.4 Production of Excited Molecules by Electron Transfer

Chapter 11: Applications

11.1 Photoelectrochemical Solar Energy Conversion

11.2 Photocatalytic Processes

11.3 Etching of Semiconductors

11.4 Light-Induced Metal Deposition

Appendices

A.1 List of Major Symbols

A.2 Physical Constants

A.3 Lattice Parameters of Semiconductors

A.4 Properties of Important Semiconductors

A.5 Effective Density of States and Intrinsic Carrier Densities

A.6 Major Redox Systems and Corresponding Standard Potentials

A.7 Potentials of Reference Electrodes

References

Index

List of Tables

7 Charge Transfer Processes at the Semiconductor–Liquid Interface

Table 7.1 Reorganization energies.

Table 7.2 Standard potentials of two-step redox systems (SCE).

8 Electrochemical Decomposition of Semiconductors

Table 8.1 Decomposition products of various semiconductor electrodes during anodic and cathodic polarization.

11 Applications

Table 11.1 Electrochemical photovoltaic cell systems. Photovoltage (

U

ph

), photocurrent (

j

ph

), fill factor (FF), efficiency (

η

).

List of Illustrations

1 Principles of Semiconductor Physics

Figure 1.1 Important unit cells (taken from [7]).

Figure 1.2 Miller indices of some important planes in a cubic crystal.

Figure 1.3 Parabolic dependence of the energy of a free electron vs wave vector.

Figure 1.4 Electron energy vs wave vector in a semiconductor.

Figure 1.5 Energy band structure of Si and GaAs. Compare with Figure 1.4 (after [11]).

Figure 1.6 Brillouin zone for face-centered cubic lattices with high symmetry points labeled (after [6]).

Figure 1.7 Optical transitions in semiconductors with an indirect bandgap.

Figure 1.8 Absorption spectra of various semiconductors.

Figure 1.9 Optical transitions in a semiconductor.

Figure 1.10 Doping of a semiconductor crystal (Ge): (a) n-type doping; (b) p-type doping.

Figure 1.11 Imperfections in a compound semiconductor (CdS).

Figure 1.12 Density of energy states near the band edges of a semiconductor vs energy.

Figure 1.13 Band structure and energy distribution of the density of states of silicon, as calculated for a large energy range. Dotted distribution is occupied by electrons (from [6]).

Figure 1.14 Band diagram, density of states, and Fermi distribution.

Figure 1.15 Arrangement for measuring carrier concentrations by the Hall effect (from [7]).

Figure 1.16 Excitation and recombination of electrons.

Figure 1.17 Quasi–Fermi levels of electrons and holes (a), at equilibrium (b), and (c) under illumination.

2 Semiconductor Surfaces and Solid–Solid Junctions

Figure 2.1 Schematic presentation of different surface potentials at the solid–vacuum interface (details in the text). (a) Metal; (b) n-type; (c) p-type semiconductor (after [1]).

Figure 2.2 Energy diagram of the semiconductor–vacuum interface in the presence of surface states.

Figure 2.3 Energy diagram of a metal–n-type semiconductor interface before and after contact: (a) without surface states; (b) with surface states.

Figure 2.4 Energy diagram of the metal–semiconductor interface for different metal work functions

Figure 2.5 Index of the interface behavior,

S

, as a function of the electronegativity differences of semiconductors (after [17]).

Figure 2.6 Electron transfer at the semiconductor–metal interface according to the thermionic emission model.

Figure 2.7 (a) Current–voltage curve for an n-type GaAs–Au Schottky junction. Au was deposited electrolytically. (b) Semilogarithmic plot of the forward dark current (after [27]).

Figure 2.8 Energy diagram of a metal–semiconductor junction for a minority carrier device. (a) Hole injection into the valence band of an n-type semiconductor under forward bias; (b) hole extraction from the valence band under reverse bias.

Figure 2.9 Energy diagram of a p–n junction under forward bias.

Figure 2.10 Ohmic contacts between metal and semiconductor. (a) and (b) Using metals forming low barriers with n- and p-type semiconductors; (c) using a metal forming a high barrier (see the text).

Figure 2.11 Energy diagram of a metal–semiconductor–metal system under bias (ohmic contacts).

Figure 2.12 Energy diagram of a metal–semiconductor Schottky junction under illumination. (a) Open circuit condition; (b) short circuit condition.

Figure 2.13 Current–voltage curve for a metal–semiconductor junction in the dark and under illumination.

Figure 2.14 Surface recombination,

s

, vs potential across the space charge layer

3 Electrochemical Systems

Figure 3.1 Potential profile across a metal–liquid interface.

Figure 3.2 A copper–zinc cell with a permeable membrane.

Figure 3.3 Potential profile for a Cu-electrolyte-Zn system.

Figure 3.4 Pt(H

2

/H

+

) reference electrode (normal hydrogen electrode (NHE)).

Figure 3.5 Energy diagram for a metal (or semiconductor)–redox system–reference electrode system.

Figure 3.6 Energy diagram for the semiconductor–vacuum, semiconductor–liquid, and liquid–vacuum interfaces;

4 Experimental Techniques

Figure 4.1 A holder for a rotating semiconductor electrode.

Figure 4.2 A measuring cell.

Figure 4.3 A potentiostatic measuring system: WE, working electrode; RE, reference electrode; CE, counter electrode.

Figure 4.4 Rotating ring disk electrode assembly.

Figure 4.5 SECM line scans across a stepped portion of a WSe

2

electrode: tip current at diferent potentials of a WSe

2

electrode in aqueous solutions. Inset: tip arrangement; tip diameter, 2 μm (after [9]).

Figure 4.6 Technique for measuring injection of minority carriers into a semiconductor electrode. (a) Geometry of a p–n junction; (b) cell arrangement.

Figure 4.7 Imaginary and real part of impedance.

Figure 4.8 Equivalent circuit.

Figure 4.9 Modulation of potential and current for a semiconductor electrode.