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A van der Waals heterojunction-based photodetector has attracted significant interest due to its potential for high-speed visible light communication (VLC) application. Herein, we report a self-powered and high-performance MXene/InGaN van der Waals heterojunction visible light mini-photodetector (mini-PD). The combination of MXene and InGaN creates a Schottky junction that effectively separates the photoinduced electron/hole pairs, resulting in a robust heterojunction structure while enhancing carrier mobility and lifetime. The mini-PD exhibits the responsivity of 6.0 A/W, a specific detection rate of 9 × 1011 Jones, and rise/decay times of 7.1/183.2 μs under 470 nm blue light (36.5 μW/cm2) without bias voltage. The results show that MXene forms a robust type-II band arrangement with InGaN, which converts the optical signal into a large electrical signal and improves the stability of the mini-PD. This work provides a strategy for high-speed VLC without external energy input that has great potential for applications such as energy-efficient communication, sensor networks, and low-sensitivity detection.

Ultraviolet (UV) photodetection has been of great importance in the fields of aerospace, space communications, and remotely sensed images. However, conventional UV photodetectors (PDs) have been facing intrinsic drawbacks of complicate structural issues and interference from ambient visible light. Therefore, wide bandgap semiconductors have attracted significant attention. Herein, self-powered PDs based on the monolithic germanium disulfide ( m-GeS2)/gallium nitride (GaN) pn heterojunction have been proposed with a large-size m-GeS2 over 2 cm2. The electronic and optical properties of the m-GeS2/GaN heterojunction are investigated via experiments and first-principles methods. The PDs reveal an impressive performance in self-powered response and high responsivity and detectivity of 16.8 mA W−1 and 1.03 × 1011 Jones, respectively. Further analyses determined that the PDs show an ultrafast photoresponse with a rise and fall time of 2 and demonstrates its enormous potential in high-performance, self-powered UV photodetection.