All‐Sprayed‐Processable, Large‐Area, and Flexible Perovskite/MXene‐Based Photodetector Arrays for Photocommunication

Abstract Flexible photodetectors (PDs) are attracting more attention due to their promising applications in wearable optoelectronic devices, bendable imaging sensors, and implantable optoelectronics. For the easy‐processable technology of massively fabricating PDs, instead of the expensive and complex high‐vacuum technique, the well‐matched work function of their active materials is essential. Herein, all‐sprayed‐processable and large‐area PDs are demonstrated on common paper based on two‐dimensional (2D) CsPbBr 3 nanosheets and conductive Ti 3 C 2 T x (MXene). Ascribed to the superior conductivity of MXene, high crystallinity of 2D CsPbBr 3 , and their well‐matched work function, the as‐prepared PDs exhibit an outstanding on/off current ratio up to 2.3 × 10 3 and a remarkable photoresponse as fast as 18 ms. Specifically, the detectivity ( D *) of 6.4 × 10 8 Jones and responsivity ( R ) of 44.9 mA W −1 under a bias of 10 V are achieved. Besides, after bending 1500 cycles, the as‐prepared PDs can still maintain the excellent flexibility and stability. Based on this, a superior‐quality and large‐area 1665 pixel sensor in 72 cm 2 (≈24 units cm −2 ) is developed, and it can clearly transmit the image of “0” to realize the photocommunication function. This work provides a low‐cost method of massively producing the flexible large‐area PDs for wearable optoelectronic devices and expanded photocommunication.