Self-powered and high responsivity photodetector based on a n-Si/p-GaTe heterojunction

Heterojunction integrated by two-dimensional/three-dimensional materials has shown great potential applications in optoelectronic devices because of its fast response speed, high specific detectivity and broad spectral response. In this work, the vertical n-Si/p-GaTe heterojunction has been designed and fabricated, which shows a high responsivity up to 5.73 A W⁻¹ and a fast response time of 20 μs at zero bias benifitting from the high efficiency of light absorption, internal photocurrent gain and strong built-in electrical field. A specific detectivity of 10¹² Jones and a broad spectral response ranging from 300 to 1100 nm can also be achieved. This work provides an alternative strategy for high-performance self-powered optoelectronic devices. (paper)