Quantitative study of localization effects and recombination dynamics in GaAsBi/GaAs single quantum wells, M.K. Shakfa, D. Kalincev, X. Lu, S.R. Johnson, D.A. Beaton, T. Tiedje, A. Chemikov, S. Chaterjee, M. Koch, J. Appl. Phys. 114, 164306 (2013)

Localization effects on the optical properties of GaAs_1-xBi_x/GaAs single quantum wells (SQWs), with Bi contents ranging from x = 1.1% to 6.0%, are investigated using continuous-wave and time-resolved photoluminescence. The temperature- and excitation density dependence of the PL spectra are systematically studied, and the carrier recombination mechanisms are analyzed. At low temperatures, the time-integrated PL emission is dominated by the recombination of localized electron-hole pairs due to the varying content and clustering of Bi in the alloy. The extracted energy scales fluctuate tremendously when the Bi content is varied with a weak tendency to increase with Bi content. Relatively low energy scales are found for the SQW with x = 5.5%, which makes it a potential candidate for long-wavelength optoelectronic devices.