Composition dependence of photoluminescence of GaAs_1-xBi_x alloys, X. Lu, D. A. Beaton, R. B. Lewis, T. Tiedje, Y. Zhang, Appl. Phys. Lett. 95, 041903 (2009)

Room temperature photoluminescence(PL) spectra have been measured for GaAs_1-xBi_x alloys with Bi concentrations in the 0.2%-10.6% range. The decrease in the PL peak energy with increasing Bi concentration follows the reduction in bandgap computed from density functional theory. The PL peak energy is found to increase with PL pump intensity, which we attribute to the presence of shallow localized states associated with Bi clusters near the top of the valence band. The PL intensity is found to increase with Bi concentration at low Bi concentrations, peaking at 4.5% Bi.