ZnSb/Ti3C2Tx 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/Ti3C2Tx MXene based flexible NIR photodetector array via a facile photolithography technology. The single ZnSb/Ti3C2Tx 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 Ti3C2Tx MXene nanoflakes, and the formed 2D van der Waals heterojunction. Thin polyethylene terephthalate (PET) substrate enables the ZnSb/Ti3C2Tx photodetector withstand bending such that stable photoelectrical properties with non-obvious change were maintained over 5000 bending cycles. Moreover, the ZnSb/Ti3C2Tx photodetectors were integrated into a 26 x 5 device array, realizing a NIR image sensing application.