Highly sensitive solar-blind deep ultraviolet photodetector based on graphene/PtSe2/β-Ga2O3 2D/3D Schottky junction with ultrafast speed

There is an emerging need for high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors with an ultra-fast response speed. Although nanoscale devices based on Ga2O3 nanostructures have been developed, their practical applications are greatly limited by their slow response speed as well as low specific detectivity. Here, the successful fabrication of two-/three-dimensional (2D/3D) graphene (Gr)/PtSe2/beta-Ga2O3 Schottky junction devices for high-sensitivity solar-blind DUV photodetectors is demonstrated. Benefitting from the high-quality 2D/3D Schottky junction, the vertically stacked structure, and the superior-quality transparent graphene electrode for effective carrier collection, the photodetector is highly sensitive to DUV light illumination and achieves a high responsivity of 76.2 mA/W, a large on/off current ratio of similar to 10(5), along with an ultra-high ultraviolet (UV)/visible rejection ratio of 1.8 x 10(4). More importantly, it has an ultra-fast response time of 12 mu s and a remarkable specific detectivity of similar to 10(13) Jones. Finally, an excellent DUV imaging capability has been identified based on the Gr/PtSe2/beta-Ga2O3 Schottky junction photodetector, demonstrating its great potential application in DUV imaging systems.

Automated summary

This study demonstrates the successful fabrication of high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors using two-/three-dimensional graphene/PtSe2/beta-Ga2O3 Schottky junction devices. The photodetector shows high responsivity, a large on/off current ratio, ultra-fast response time, remarkable specific detectivity, and excellent DUV imaging capability, indicating great potential for DUV imaging systems.