We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed an...We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states.There are two different mechanisms for the origin of the PL intensity quenching for the Al In As Sb digital alloy.The high-temperature activation energy E_(1)is positively correlated with the interface thickness,whereas the low-temperature activation energy E_(2)is negatively correlated with the interface thickness.A quantitative high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)study shows that the interface quality improves as the interface thickness increases.Our results confirm that E_(1)comes from carrier trapping at a state in the In Sb interface layer,while E_(2)originates from the exciton binding energy due to the roughness of the Al As interface layer.展开更多
基金Project supported by the National Key Technologies Research and Development Program of China(Grant Nos.2019YFA0705203,2019YFA070104,2018YFA0209102,and 2018YFA0209104)the Major Program of the National Natural Science Foundation of China(Grant Nos.61790581,62004189,and 61274013)+2 种基金the Aeronautical Science Foundation of China(Grant No.20182436004)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22)the Research Foundation for Advanced Talents of the Chinese Academy of Sciences(Grant No.E27RBB03)。
文摘We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states.There are two different mechanisms for the origin of the PL intensity quenching for the Al In As Sb digital alloy.The high-temperature activation energy E_(1)is positively correlated with the interface thickness,whereas the low-temperature activation energy E_(2)is negatively correlated with the interface thickness.A quantitative high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)study shows that the interface quality improves as the interface thickness increases.Our results confirm that E_(1)comes from carrier trapping at a state in the In Sb interface layer,while E_(2)originates from the exciton binding energy due to the roughness of the Al As interface layer.
