Highly responsive self-driven broadband photodetector based on MoS2 nanorods/β-Ga2O3 heterojunction

Abstract

Gallium oxide (Ga2O3) has drawn significant interest in developing high-performance deep-ultraviolet photodetector, but detection of broadband range from ultraviolet C to near-infrared remains a substantial challenge. The construction of heterojunction effectively broadens the spectral range for fabricating broadband photodetection devices with exciting optical and electrical properties. This work introduces a heterojunction comprised of horizontally aligned MoS2 nanorods on β-Ga2O3 nanogranules. The high-performing developed MoS2/β-Ga2O3 device operates in a self-driven mode in the broad spectral range from ultraviolet C -visible-near infrared (UVC-VIS-NIR). The device exhibits an ultralow dark current of 79 nA and a maximum responsivity of 94.92, 7.97, and 44.04 mAW−1 for UV (266 nm), Vis (625 nm), and NIR (950 nm) light illumination in self-driven conditions. Furthermore, the fabricated device shows the highest responsivity of 4.2 × 104 mAW−1, with a high external quantum efficiency of 1.97 × 104% and extremely low noise equivalent power of 4.03 × 10−14 WHz−1/2, under 266 nm light illumination at an applied bias of 5V. This study paves the way to develop MoS2/β-Ga2O3 based broadband photodetector for constructing high-performance self-driven optoelectronics devices with low power consumption.