Photoluminescence studies on GaxIn1−xSb alloys

Abstract Photoluminescence experiments are performed on gallium indium antimonide alloy (Ga x In 1− x Sb) at low temperatures; x varies between 1 and 0.6. This work permits us to study the composition dependence of the different photoluminescence lines. From the free exciton line we obtain the variation of the band gap E 0g with x at 4.2 K. The bowing parameter c deduced from our experimental results is 0.33 (this value is in good agreement with the theoretical value deduced by Van Vechten 0.36). The photoluminescence peak of the acceptor level responsible of the p character of GaSb is studied in particular on the alloy. This line becomes less intense with decreasing x and on the other hand its ionisation energy with respect to the Γ 8 level does not vary significantly.