Abnormal carrier thermalization dynamics at type-II interface in InP nanomembranes

Type-II InP wurtzite-zincblende (WZ-ZB) nanostructures are promising in chip-scale photonic interconnects due to their exceptional electron mobility and optoelectronic properties. However, their rise time characteristics, crucial for device response speed, have not been thoroughly explored. This study employs time-resolved photoluminescence to investigate how spatial separation of carriers in type-II InP nanomembrane heterostructures affects the rise time. Our findings indicate that strong localization effects and potential wells reduce carrier generation efficiency at low temperatures, leading to prolonged rise times. As the temperature increases, the rise times in the WZ, ZB, and interfacial WZ-ZB regions decrease, as carriers gain thermal energy, enhancing their ability to overcome local potential wells. Simultaneously, this thermal excitation facilitates carrier delocalization, influencing direct band-to-band transitions and accelerating the generation process. These results emphasize the importance of interface engineering in optimizing carrier dynamics, which can enhance the performance of high-speed optoelectronic devices to meet the demands of future communication technologies.

Duke Scholars

Author Changcheng Zheng DKU Faculty