Flexible Imager Based on Graphene‐Silicon Heterojunction Array

ABSTRACT Flexible imagers play fundamental roles in electronic eyes, biomedical monitoring, robotics, and satellite technologies, while crosstalk‐free multiplexing of large pixel arrays remains a bottleneck. Two popular ways to mitigate crosstalk require external components — passive matrices with blocking diodes and active matrices with phototransistors/active backplanes, which increase fabrication complexity, reduce fill factor, and limit mechanical adaptability. These limitations are overcome by a flexible imager based on a self‐blocking graphene–silicon heterojunction array. This intrinsic self‐blocking mechanism enables crosstalk‐free row–column readout with a minimalist imaging‐plane architecture comprising only photosensitive area and orthogonally patterned electrodes. This simple two‐terminal pixel structure achieves a high fill factor of 36% and a pixel density of 42 PPI and is readily scalable to large‐deformation stretchable configurations. Individual pixels exhibit high stability, broadband sensitivity from ultraviolet to near‐infrared, an ultrafast 80‐ns rise time, and a wide linear dynamic range (100 dB under 660 nm). Real‐time imaging with multiple wavelengths (532 nm, 1064 nm) and dynamically varying curvatures is demonstrated using FPGA‐based readout. By coupling structural simplicity with high performance, this work establishes a generalizable platform for self‐blocking metal–semiconductor optoelectronics, offering new routes toward scalable, mechanically adaptive, and crosstalk‐free imaging systems relevant to emerging angstrom‐thick 2D metals.