Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial reso...Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial resolution ofσCL=1.8 nm.The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range.Demonstrating the capability of resolving the 10.8 nm separated,ultra-thin quantum wells,a cathodoluminescence profile was taken across individual ones.Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe,the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.展开更多
基金National Key Research and Development Program of China(2017YFE0100300)Science Challenge Project(TZ2016003)+1 种基金National Natural Science Foundation of China(61734001,61521004,61774004)Deutsche Forschungsgemeinschaft(Research Instrumentation Program INST272/148-1,Collaborative Research Center SFB 787)。
文摘Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial resolution ofσCL=1.8 nm.The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range.Demonstrating the capability of resolving the 10.8 nm separated,ultra-thin quantum wells,a cathodoluminescence profile was taken across individual ones.Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe,the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.
