Two-dimensional (2D) self-driven photodetectors have attracted extensive attention due to the fast photoresponse, low energy consumption and high flexibility. Recently, the metal–semiconductor-metal (MSM) structures with asymmetrical 2D semiconductor channel are exploited for the self-driven photodetection. However, the mechanism is still in dispute and the channel has not yet been forward to monolayer. Here, a self-driven MSM photodetector is fabricated with the directly-grown monolayer WSe₂ which is asymmetrically patterned by the controllable scratching lithography. The self-driven behavior mainly originates from the asymmetry of both conduction channel and the Schottky junctions. With the photovoltaic effect driven by asymmetry, the device exhibits linear photoresponse with responsivity of 1.4 mA/W, detectivity of 10¹⁰ Jones, dark current level of 0.1 pA and response speed of tens of milliseconds. Moreover, performances show highly gate-tunable characteristics due to the tunable Schottky barriers. This work provides a new route towards self-driven photodetectors based on 2D materials.

二维（2D）自驱动光电探测器由于具有快速的光响应、低能耗和高灵活性而受到广泛关注。最近，具有不对称二维半导体通道的金属-半导体-金属（MSM）结构被用于自驱动光电检测。然而，该机制仍存在争议，通道尚未转发到单层。_{此处，使用直接生长的单层 WSe 2}制造了自驱动 MSM 光电探测器这是通过可控的刮擦光刻不对称图案化的。自驱动行为主要源于传导通道和肖特基结的不对称性。利用不对称驱动的光伏效应，该器件表现出线性光响应，响应率为1.4 mA/W，探测灵敏度为10 ¹⁰琼斯，暗电流水平为0.1 pA，响应速度为数十毫秒。此外，由于可调谐的肖特基势垒，性能表现出高度可调谐的特性。这项工作为基于二维材料的自驱动光电探测器提供了一条新途径。