Recombination lifetime of carriers in GaAs-GaAlAs quantum wells near room temperature

Abstract

The lifetime τ of carriers in undoped GaAs-GaAlAs quantum well structures was studied at room temperature by using the photoluminescence phase shift method. We have found that τ is inversely proportional to the carrier concentration under the excitation levels of 1016–1018 cm−3. The comparison of these results with both the theory of band-to-band recombination and the measured dependence of τ on the carrier concentration at 77 K suggests that the carrier recombination near room temperature is dominated by this band-to-band recombination process. We also discussed the dependence of τ on the quantum well thickness.