OPTICAL-PROPERTIES OF HIGH-QUALITY INGAAS/INALAS MULTIPLE QUANTUM-WELLS

We have measured the narrowest half-width at half-maximum photoluminescence linewidth of 2.8 meV, in 40-period lattice-matched In0.53Ga0.47As/In0.52Al0.48As multiple quantum wells, grown by molecular-beam epitaxy with growth interruption. A simple analysis of the linewidth suggests that the structure has near perfect interfaces. Temperature-dependent photoluminescence linewidth data indicate impurity incorporation due to the growth interruption. However, the high quality of the multiple quantum well is not impaired as is seen in the room-temperature absorption data, where excitonic features up to n = 3 sublevel are clearly seen. Carrier lifetime in this multiple-quantum-well system has been measured, we believe for the first time, using the picosecond photoluminescence correlation technique. A lifetime of 860 ps is obtained, which is similar to the value obtained for high-quality GaAs/AlGaAs and In0.53Ga0.47As/InP quantum wells. This further confirms the high quality obtained in this ternary material system using growth interruption.