High-performance light trajectory tracking and image sensing devices based on a γ-In2Se3/GaAs heterostructure

Abstract

In this work, we present the assembly of a γ-In₂Se₃/GaAs heterostructure-based photodetector linear array composed of 1 × 10 device units. The layered γ-In₂Se₃ films with a well-defined pattern are deposited directly onto a planar GaAs substrate via radio-frequency (RF) magnetron sputtering deposition assisted by a pre-photolithography process. The as-fabricated heterojunction exhibits an apparent photovoltaic effect, which endows the device with a function to operate as a self-driven photodetector. The critical photoresponse performance parameters in terms of the I_light/I_dark ratio, responsivity (R), specific detectivity (D*) and response speed can reach 1.29 × 10⁴, 0.25 A W⁻¹, 7.34 × 10¹² Jones and 23.6/146.7 μs (rise/fall times), respectively, upon 660 nm light irradiation at 0 V. What is more, further device evaluation reveals that the photodetector array shows good uniformity with a minor unit-to-unit variation. The above merits endow the photodetector array with the ability to monitor a moving optical signal and to record an “E” image produced by visible illumination. It is believed that the present photodetector array is very promising for some optoelectronic purposes such as real-time light trajectory tracking and visible light image sensing applications.