Chapter 9 Electroreflectance at Semiconductors

Publisher Summary This chapter discusses electroreflectance at semiconductors. Considerable controversy surrounds the description of the potential distribution at the surface of a semiconductor electrode in contact with a concentrated electrolyte. It is highly desirable that the case applicable to a given experimental configuration should be known, and known with some precision, as interpretation of, for example, any photocurrent observed is likely to be sensitively dependent on the potential distribution. For this reason, a variety of techniques have been developed to study the internal field and potential. The earliest technique to be used extensively is the measurement of the a.c. current response to an applied a.c. potential. Provided very small amplitude a.c. signals are used, the resultant equations can be linearized and solved directly. The optical absorption cross-section depend sensitively on the surface from which reflection takes place and the relative orientation of the surface and the electric vector of the incoming radiation.