Enhanced and Polarity-Switchable Photoresponse in MoS2 with Asymmetric Metal Contact via Pressure Band Engineering

Abstract

The burgeoning demand for efficient photoelectric devices has ignited a fervent exploration of strategies for regulating their performance. Herein, the enhancement and polarity switching in the photoresponse of MoS₂ photovoltaic devices with asymmetric electrodes are showcased by employing a pressure band engineering strategy. Specifically, the photoresponse of the Pt/MoS₂/Ag setup escalates from 2 A W⁻¹ at 0.5 GPa to 4 A W⁻¹ at 2.3 GPa, showcasing a twofold enhancement, while displaying a successive decrease under higher pressure. Unforgettable is the fascinating and uncommon polarity switching behavior observed at 5.0 GPa in the Pt/MoS₂/Au device, accompanied by a gradual decrease in photoresponse, implying its potential applications in logic gate devices. The dynamic evolution of photoresponse in Pt/MoS₂/Ag and Pt/MoS₂/Au devices can be ascribed to the variations in the bandgap, electron affinity, and work function of MoS₂ under high pressure, arising from the intensified interlayer interactions within MoS₂. These findings validate the feasibility of enhancing photovoltaic device performance under pressure and unveil new avenues for exploring, manipulating, and comprehending high-efficiency and multifunction photoelectric devices.