DETERMINING BAND OFFSETS USING SURFACE PHOTOVOLTAGE SPECTROSCOPY - THE INP IN0.53GA0.47 HETEROJUNCTION/

A direct technique for determining band offsets at semiconductor heter ojunctions is presented, which is applicable to at least any type I he terojunction, where the top layer doping is sufficiently low. The tech nique is based on surface photovoltage spectroscopy measurements as a function of overlayer thickness, A numerically simulated example shows that the band offset is a very strong function of the critical overla yer thickness, at which the overlayer contribution to the surface phot ovoltage spectrum appears, The method is applied to the technologicall y important InP/InGaAs heterojunction and is shown to yield the common ly accepted band offset value. (C) 1996 American Institute of Physics.