PHOTOLUMINESCENCE STUDIES OF In_(0.25)Ga_(0.75)As-GaAs STRAINED QUANTUM WELLS UNDER HIGH PRESSURE

We report the results of the photoluminescence(PL)studies of the Ino.jsGao.r$As-GaAs strained quantum wells(QW’s)at 77K and at high pressures up to 5Okbar.The pressure coefficients of the T valley of(InGa)As-GaAs strained QW’s are presented for the first time.The crossover between the energy level in the well and the X valley in the barrier GaAs has been observed.The ratio of the conduction band offset to valence band offset in In_(0.25)Ga_(0.75)As-GaAs heterojunction was determined to be Qc=ΔEc:ΔEv=0.68:0.32.Some discussions about GaAs-Al0.3Ga0.7As QW’s are also presented.