2D Carrier Localization at the Wurtzite-Zincblende Interface in Novel Layered InP Nanomembranes

The successful application of semiconductor nanostructures in devices has attracted intense interest in their carrier dynamics. Here an in-depth investigation of the carrier dynamics in novel layered InP nanomembranes with a large area of atomically sharp wurtzite-zincblende (WZ-ZB) interface is conducted for the first time by using various spectroscopic techniques. Two kinds of type II transitions in these nanomembranes are observed, which are from the ZB/WZ type II planar interface and stacking fault-induced ZB segments in the WZ phase layer. A strong two-dimensional carrier localization effect in the flat type II interface is demonstrated at low temperatures. As the excitation fluence increases, the occurrence of state filling can play an important role in the emission energy and lifetime of this type II transition. Thermal transfer of carriers from the type II interface 2D localization to the ZB conduction band results in the quenching of type II transitions at room temperature. Interesting novel emission polarization behaviors of different transitions in this InP nanomembrane are also highlighted. The polarization direction of the WZ and ZB emissions, as well as two kinds of type II transitions, are found to be perpendicular to each other. This study thus provides a deeper insight into the type II transitions in semiconductor nanostructures.