ZnSb/Ti₃C₂T _x MXene van der Waals heterojunction for flexible near-infrared photodetector arrays

Two-dimension (2D) van der Waals heterojunction holds essential promise in achieving high-performance flexible near-infrared (NIR) photodetector. Here, we report the successful fabrication of ZnSb/Ti₃C₂T _x MXene based flexible NIR photodetector array via a facile photolithography technology. The single ZnSb/Ti₃C₂T _x photodetector exhibited a high light-to-dark current ratio of 4.98, fast response/recovery time (2.5/1.3 s) and excellent stability due to the tight connection between 2D ZnSb nanoplates and 2D Ti₃C₂T _x MXene nanoflakes, and the formed 2D van der Waals heterojunction. Thin polyethylene terephthalate (PET) substrate enables the ZnSb/Ti₃C₂T _x photodetector withstand bending such that stable photoelectrical properties with non-obvious change were maintained over 5000 bending cycles. Moreover, the ZnSb/Ti₃C₂T _x photodetectors were integrated into a 26 × 5 device array, realizing a NIR image sensing application.