Electroreflectance spectroscopy of InGaAs

by Hsu, Chih-cheng

The electroreflectance spectra(ER) have been measured on InxGa1-xAs film under various bias(Vbias), and they have exhibited many Franz-Keldysh Oscillations(FKOs) above band-gap energy. Their strength of field in the film can be obtained by the periods of FKOs. Due to many oscillations of FKOs, the Fast Fourier transform can be applied to separate heavy- and light-hole transitions. The relation between F and Vbias was nearly linear. FKOs were observable at a large range of photon energy(£_E). The mean free path of carriers can be estimated from the relation between £_E and F. It was compared with the range of order obtained from X-ray diffraction.