Influence of junctions on photoluminescence decay in thin-film devices

The photoluminescence lifetime of III-V thin films is a major tool for the determination of minority-carrier lifetime. Prior work has dealt with the effects of surface recombination for various device geometries. Other work has shown the effect of self-absorption and photon recycling on the effective lifetime. We describe deep homojunctions thin-film devices. Model calculations show that the effective lifetime, as measured in the photoluminescence experiment, is always less than the bulk minority-carrier lifetime. In high-mobility materials, the effective photoluminescence lifetime may be dominated by diffusion and unrelated to recombination. An analysis of the data produces the minority-carrier mobility.