ELECTROLYTE ELECTROREFLECTANCE SPECTRA OF PURE AND DOPED GAAS

The electrolyte electroreflectance spectra of pure GaAs and of doped G aAs with various concentrations are studied at room temperature. For t he case of pure GaAs, the typical modulation spectrum of E(0) caused b y exciton dissociation in electric field is observed. For the case of doped GaAs, not only the Franz-Keldysh oscillations, but also the line broadening and the shifts of spectrum to the high energy region are o bserved. The theory of non-uniform electric field is applied in the an alysis of these experimental results.