Semiconductor two dimensional (2D) materials have shown great potential in optoelectronic devices because of their high carrier mobility and very thin thickness. Recently, many groups have exploited the heterojunction structures based on semiconducting 2D materials for photovoltaic applications as ultrathin p-n didoes. For high-performance photovoltaic devices, the electron-hole balance is an important parameter because it has effect on the formation of the built-in field across the device. In this study, we exhibit multi-layer black phosphorus (BP)/WS2 p-n heterojunction device and demonstrate the photovoltaic effect of the device by electrostatically controlling carrier concentration into BP. The gate-controlled heterojunction device exhibits a high current rectification of 103, external quantum efficiency of 4.4% under the 405-nm laser illumination, and solar efficiency of 4.6% under the AM 1.5 solar spectrum. Our works suggest that making a balance of charge carriers in the 2D heterojunction p-n diode is highly prioritized for the high performance 2D heterojunction photovoltaic device.
5:00 PM–7:00 PM Apr 24, 2019 (US - Arizona)
PCC North, 300 Level, Exhibit Hall C-E