QUANTITATIVE SURFACE PHOTOVOLTAGE SPECTROSCOPY OF SEMICONDUCTOR INTERFACES

A comprehensive and quantitative method for extracting the important parameters of interface states is presented. The method is based on wavelength-, intensity-, and time-resolved surface photovoltage spectroscopy, as well as on measurements as a function of the thickness of an overlayer. Data analysis provides detailed information about interface state properties, including their energy position and distribution, density, and the transition probabilities, i.e. their thermal and optical cross sections. It is also possible to distinguish between surface and bulk states, and determine the spatial site of the states in the case of a heterostructure. Experimental examples for various III-V and II-VI compound semiconductors are given.