Ti3C2Tx MXene-RAN van der Waals Heterostructure-Based Flexible Transparent NIR Photodetector Array for 1024 Pixel Image Sensing Application

The enriched surface functional group such as -OH termination and unique 2D structure of Ti3C2Tx MXene provide the feasibility to form hydrogen bonds with organic photosensitive materials as van der Waals heterostructures, thus can realize the improved photoresponsivity of near infrared (NIR) photodetectors (PDs). In this work, an organic-inorganic van der Waals heterostructure-based NIR PD array is designed using Ti3C2Tx MXene as conductive electrodes and RAN film as active materials (Ti3C2Tx-RAN PDs). The on-off ratio of the fabricated devices shows 6.25 times higher than that of PDs using thermal evaporated Au electrode (Au-RAN PDs) under 1064 nm laser excitations. The fabricated Ti3C2Tx-RAN NIR PDs also possess outstanding mechanical stability with no obvious photoresponse degradation under different bending states and high transparency with a transmittance above 70% in the visible region. Owing to the high performance of the Ti3C2Tx-RAN PDs, a 1024-pixel (32 x 32) image sensor array is fabricated to achieve delicate, vivid, and higher resolution imaging of a "deer," opening up a new avenue for the biomimetic vision and flexible wearable accurate image sensing.