Surface and Defect States in Semiconductors Investigated by Surface PhotovoltageDefects in Semiconductors

The aim of this chapter is a throughout description and discussion of surface photovoltage spectroscopy. The basic physical principles, experimental details, and relevant results of the method are described, and the capability of the method to extract material properties like optical band gap and defect-related states is discussed. The method presents several advantages, as it allows for the identification of conduction versus valence band nature of the defect-related transitions and the defect level positions within the band gap. Moreover, it allows for the detection of relatively low densities of surface defects as well as their cross-sections. The application of the method to different materials and structures is discussed, ranging from bulk semiconductors to low-dimensional systems, to nanostructures.