Journal of Vacuum Science & Technology B, Vol.14, No.3, 2212-2215, 1996
High-Index Orientation Effects of Strained Self-Assembled InGaAs Quantum Dots
Optical characterization of strained InGaAs/GaAs quantum dots grown by molecular beam epitaxy on (001) and (n11)B, where n = 1, 2, 3, 5, and 7 orientations is reported in this work. Quantum dot photoluminescence emission shows remarkable orientation effects, presented in peak shape, full width at half-maximum, and integrated intensity. Quantum dots grown on the (711)B plane demonstrate high quantum efficiency : integrated photoluminescence ratio between quantum dots and quantum well is about 10. Our results indicate an enhancement of the quantum dots onset thermal quenching energy by a factor of 2.5 for all orientations. Activation energy for thermal stimulated electron-hole emission in quantum dots is 2-5 times higher than in quantum wells. Photoluminescence polarization measurements show strong in-plane dependence caused by the quantum dots’ structural anisotropy.
Keywords:MOLECULAR-BEAM EPITAXY