A PHOTOMODULATED SPECTROSCOPY STUDY OF INXGA1-XAS/GAAS SUPERLATTICES AND QUANTUM-WELLS

We present here a detailed study of photomodulated transmission and reflectivity at room and liquid-nitrogen temperatures of a series of In(x)Ga(1-x)As/GaAs superlattices and a single quantum well. Our samples span a variety of alloy compositions and quantum-well widths. We compare the results of our measurements with the predictions of an envelope-function calculation, which includes wave-vector dependence of the minibands. This comparison allows identification of several spectral features unmistakably arising from miniband dispersion. Also, accurate determination is made of the band-offset parameter, whose value is discussed in the context of those obtained by other authors.69117836784