Novel P-Type Wide Bandgap Manganese Oxide Quantum Dots Operating at Deep UV Range for Optoelectronic Devices

Abstract

Wide bandgap semiconductor (WBGS)-based deep UV (DUV) devices lag behind those operating in the visible and IR range, as no stable p-type WBGS that operates in the DUV region (<300 nm) presently exists. Here, solution-processed p-type manganese oxide WBGS quantum dots (MnO QDs) are explored. Highly crystalline MnO QDs are synthesized via femtosecond-laser ablation in liquid. The p-type nature of these QDs is demonstrated by Kelvin probe and field effect transistor measurements, along with density functional theory calculations. As proof of concept, a high-performance, self-powered, and solar-blind Schottky DUV photodetector based on such QDs is fabricated, which is capable of detecting under ambient conditions. The carrier collection efficiency is enhanced by asymmetric electrode structure, leading to high responsivity. This novel p-type MnO QD material can lead to cost-effective industrial production of high-performance solution-processed DUV optoelectronics for large-scale applications. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim