Exploring conduction mechanism and photoresponse in P-GaN/n-MoS2 heterojunction diode

Abstract

Mixed-dimensional heterostructures have shown their potential in electronic devices. However, their functionality is limited by a complete understanding of the contacts and the current transport behavior. Here, we explore the electrical properties of the P-n heterojunction diode fabricated using p-type gallium nitride and layered molybdenum disulfide. The resulting P-n diode is rectifying in nature with current rectification of three orders of magnitude. The careful choice of Ohmic contacts on both the semiconductors reveals distinctly rectifying behavior of the heterojunction diode. The as-fabricated diode is tested at various temperatures, and the conduction mechanism in the device is analyzed based on the temperature dependent electrical characterizations. In addition, photoresponse characterization reveals that the P-n heterojunction is highly sensitive to a 405 nm laser with a high responsivity of 444 A/W at a reverse bias voltage of 5 V and shows photovoltaic behavior. The heterojunction diode acts as a self-powered photodetector. Our findings show the potential of the MoS2/GaN heterojunction in highly efficient photodetector applications.