Temperature-dependent carrier dynamics of InP/InGaP quantum structures grown at various growth temperatures using migration-enhanced epitaxy

Abstract

The optical properties of InP/InGaP quantum structures (QSs) grown using migration-enhanced molecular beam epitaxy at growth temperatures ranging from 440 to 520 degrees C were investigated using temperature-dependent photoluminescence (PL) and time-resolved PL spectroscopies. As the growth temperature increased from 440 to 520 degrees C, the PL peak energies originating from quantum dots and quantum dashes were blue-shifted, which is attributed to the intermixing of InP and Ga in the InGaP wetting layer. The structural and luminescence properties of InP/InGaP QSs strongly depend on the growth temperatures. The sample grown at 460 degrees C exhibited the strongest PL intensity at room temperature. In addition, as the temperature increased from 10 to 220 K, the PL decay time of the sample grown at 460 degrees C increased up to 100 K and then, gradually decreased up to 220 K. The PL decay times of the sample grown at 520 degrees C increased up to 60 K and then, rapidly decreased up to 120 K. The strongest PL intensity at room temperature and the longest decay time at 100 K for the sample grown at 460 degrees C indicate that the temperature of 460 degrees C is optimal for the formation of the InP/InGaP QSs.