Suppressing photoexcited electron-hole recombination in MoSe/WSe lateral heterostructures interface-coupled state engineering: a time-domain study

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2020-10, Vol.8 (39), p.2621-2628
• Main Authors: Zhou, Zhaobo, Zhang, Yehui, Zhang, Xiwen, Niu, Xianghong, Wu, Guangfen, Wang, Jinlan
• Format: Article
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d0ta06626e

Photoexcited carrier dynamics at the interface play a vital role in two-dimensional heterostructure-based photovoltaic and photoelectric devices. This study systematically investigates how the interface morphologies ( i.e. , alloy and sharp interfaces) control the photogenerated carrier transfer and electron-hole recombination processes in MoSe 2 /WSe 2 lateral heterostructures. It is revealed that both interfaces exhibit a remarkable photogenerated carrier separation rate within a few picoseconds. More surprisingly, the sharp interface exhibits an exceptional long carrier lifetime up to 1 nanosecond, which is longer than that of the alloy interface by a factor of 1.5. This is ultimately attributed to the vanishing interface-coupled states that effectively limit the transition channel and suppress the electron-hole recombination. This study provides insights into the photogenerated carrier dynamics in heterostructure interfaces and sheds light on the rational design of high-performance transition metal dichalcogenide heterostructure-based photovoltaic and photoelectric devices. Interface-coupled states play a vital role in photoexcited carrier lifetime of two-dimensional lateral heterostructure-based photovoltaic and photoelectric devices.