PHOTOMODULATED TRANSMISSION SPECTROSCOPY OF INXGA1-XAS GAAS MQWS UNDER HYDROSTATIC-PRESSURE/

We report the results of a comprehensive investigation of the dependen ce of various intersubband transitions within InxGa1-xAs/GaAs multiple quantum wells (MQWs) on hydrostatic pressure. Several well-defined sp ectral features associated with the transitions of either heavy hole o r light hole valence bands to the confined conduction subbands and the GaAs fundamental band gap transition are observed for all the samples under different pressures. It is demonstrated experimentally that the pressure coefficients for the intersubband transitions differ from th at of the bulk counterparts in InxGa1-xAs, and are both composition an d well-width dependent. The physical reasons which may be responsible for the abnormal behavior of the pressure coefficients of the intersub band transitions in the MQWs are discussed.