Surface photovoltage (SPV) techniques provide information about photoactive materials with respect to charge separation in space. This book aims to share experience in measuring and analyzing SPV signals and addresses researchers and developers interested in learning more about and in applying SPV methods. For this purpose, basics about processes in photoactive materials and principles of SPV measurements are combined with examples from research and development over the last two decades. SPV measurements with Kelvin probes, fixed capacitors, electron beams and photoelectrons are explained. Details are given for continuous, modulated and transient SPV spectroscopy. Simulation principles of SPV signals by random walks are introduced and applied for small systems. Application examples are selected for the characterization of silicon surfaces, gallium arsenide layers, electronic states in colloidal quantum dots, transport phenomena in metal oxides and local charge separation across photocatalytic active crystallites. Sample Chapter(s) Preface Chapter 1: Light-Induced Charge Separation and Surface Photovoltage Contents: Preface About the Authors Symbols and Abbreviations Light-Induced Charge Separation and Surface Photoactive Measurement Techniques of Surface Photovoltage Signals Practical Aspects of Surface Photovoltage Measurements Random Walk Simulation of Surface Photovoltage Signals in Small Systems Selected Applications of Surface Photovoltage Techniques Bibliography Index Readership: Young researchers and PhD students interested in the characterization of electronic properties of photoactive materials.