Photoluminescence studies of In0.25Ga0.75As-GaAs strained quantum wells under high pressure

We report the results of the photoluminescence (PL) studies of the In0.25Ga0.75As-GaAs strained quantum wells (QW's) at 77K and at high pressures up to 50kbar. The pressure coefficients of the Γ 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 In0.25Ga0.75As-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.