Solar-blind UV communication based on sensitive β -Ga2O3 photoconductive detector array

In this work, a solar-blind UV photodetector array is fabricated and discussed, based on a metalorganic chemical vapor deposition-grown β-Ga2O3 thin film, toward optical communication application. The high-performance photodetector unit shows a significant photo-to-dark current ratio of 3.4 × 105, a high responsivity of 61.3 A/W, an external quantum efficiency of 3 × 104%, a specific detectivity of 5.2 × 1014 Jones, and a fast response time of 35 ms. In addition, a solar-blind UV/visible light rejection ratio of 2.43 × 102 is achieved, suggesting decent spectral selectivity. For the array, the maximum photocurrent standard deviation is below 12% for every group with a similar layout arrangement. Furthermore, the dark current is at picoampere level, leading to low background noise for the optical communication system. Taking the 50% photocurrent value as the readout threshold line to avoid interference from the exterior meanwhile retaining about 500 on/off cycles, the optical communicated result shows effective outputting information “NJUPT2023” coming from a total of 256 “1” and “0” signals.