High-performance self-powered MoS1.2Se0.8 lateral homojunction photodetector with broadband spectrum response

Self-powered photodetector plays a key role in lower power consumption operation in the next-generation optoelectronic system. In recent years, two-dimensional (2D) materials van der Waals lateral homojunction has revealed exceptional potential in the self-powered photodetector. Here, we propose a n–n+ lateral homojunction photodetector based on the intrinsic thickness-dependent bandgap of 2D semiconductor material MoS1.2Se0.8. The photodetector has a pronounced self-powered feature with gate-tunable photovoltaic response and exhibits remarkable zero-bias performance with a photoresponsivity of 4.35 A/W and a specific detectivity of 1.49 × 1011 Jones. Furthermore, the photodetector maintains superior performance across a broad spectral range from 405 to 808 nm. This work not only validates the significant potential of thickness-modulated lateral homojunction in self-powered photodetection but also establishes a versatile platform for developing advanced optoelectronic devices through band structure engineering in 2D material systems.