Charge Management Enables Efficient Spontaneous Chromatic Adaptation Bipolar Photodetector

Solution-processed photodetectors have emerged as promising candidates fornext-generation of visible-near infrared (vis–NIR) photodetectors. This isattributed to their ease of processing, compatibility with flexible substrates,and the ability to tune their detection properties by integratingcomplementary photoresponsive semiconductors. However, the limitedperformance continues to hinder their further development, primarilyinfluenced by the difference of charge transport properties between perovskiteand organic semiconductors. In this work, a perovskite-organic bipolarphotodetectors (PDs) is introduced with multispectral responsivity, achievedby effectively managing charges in perovskite and a ternary organicheterojunction. The ternary heterojunction, incorporating a designed NIRguest acceptor, exhibits a faster charge transfer rate and longer carrierdiffusion length than the binary heterojunction. By achieving a more balancedcarrier dynamic between the perovskite and organic components, the PDachieves a low dark current of 3.74 nA cm−2at−0.2 V, a fast response speedof<10μs, and a detectivity of exceeding 1012Jones. Furthermore, abioinspired retinotopic system for spontaneous chromatic adaptation isachieved without any optical filter. This charge management strategy opensup possibilities for surpassing the limitations of photodetection and enablesthe realization of high-purity, compact image sensors with exceptional spatialresolution and accurate color reproduction.