Interfacial Diffusion Enable Broad-Band Response in Photodetector based on In2Se3/GaAs Heterojunction

Infrared (IR) photodetectors play a crucial role in modern technologies due to their ability to operate in various environmental conditions. This study developed high-performance In 2 Se 3 /GaAs interdiffusion heterostructure photodetectors with broadband response using liquid-phase method. It is believed that an InGaAs layer and In 2 Se 3 have been formed at the interface through the mutual diffusion of elements, resulting in a detection spectral range spanning from 0.45 to 2.7 µm. Consequently, the In 2 Se 3 /GaAs photodetector exhibits notably low noise equivalent power of 6.21 × 10 −15 WHz -1/2 at 1000 Hz, high photoresponsivity ( R ) and detectivity ( D* ) of 16.22 mA/W and 4.01 × 10 11 Jones under 0 V with 630 nm wavelength, respectively. At 1550 nm, it achieves a R of 0.43 µAW -1 and D* of 1.07 × 10 8 Jones under 0 V. This strongly suggests that the interdiffused In 2 Se 3 /GaAs heterostructure is a high performance and low-cost material for broadband responsive photodetectors.