Ultra-wide and self-powered WSe2/4H-SiC hybrid-dimensional heterojunction photodetector with rapid response toward multifunctional applications

Broadband self-powered photodetectors have attracted great attention owing to their capacity to detect a wide range of wavelengths and save energy. However, the majority of existing broadband photodetectors are limited in their detection range by the material bandgap, making it difficult to achieve detection from ultraviolet to infrared wavelength, and the response performance is not uniform for each waveband. Additionally, a significant disparity persists between self-powered photodetectors and conventional semiconductor photodetectors with regard to pivotal photodetection parameters, such as responsivity. To address these problems, a broadband self-powered photodetector based on two-dimensional WSe2/three-dimensional 4H-SiC heterojunction is proposed. The wide bandgap of 4H-SiC and the narrow bandgap of WSe2, in conjunction with the built-in electric field of the heterojunction and the metal/semiconductor interface, enable the device to detect light from 200 to 1100 nm and achieve a uniform high-performance response to the ultraviolet, visible, and infrared wavelengths simultaneously. Under 275 nm illumination (Vds = −1 V), the device demonstrates a responsivity and detectivity of 25.7 A/W and 3.85 × 1012 Jones, respectively, and exhibits an ultra-fast rise/decay time of 42/42 μs under 635 nm illumination (Vds = −1 V). Moreover, under Vds = 0 V and 635 nm illumination, the responsivity and detectivity of the device are 1.22 A/W and 2.67 × 1011 Jones, respectively. The device exhibits great capability in high-performance, broadband, self-powered light detection, providing a new direction for the development of next-generation energy-saving, high-sensitivity optoelectronic integration technology.