Ultra‐Sensitive and Low‐Power‐Consumption Organic Phototransistor Enables Nighttime Illumination Perception for Bionic Mesopic Vision

Abstract Emulating human vision using solid‐state devices is critical in the fields of robotics, artificial intelligence, and visual prostheses, driving intense research interest. However, bionic vision devices made from routine structures suffer from low light‐perception sensitivity to nighttime low illuminations and high power consumption, impeding their applications in many advanced scenarios from nighttime autopilot to night vision neuroprosthesis. Here, an ultrasensitive and low‐power‐consumption organic phototransistor that consists of a unique Schottky‐barrier structure and separated light absorption and carrier transport layers is reported. This device design shuns the introduction of trap states into the carrier transport route, which guarantees an ultra‐steep subthreshold swing and thus significantly amplifies the photocurrent while lowering operation voltage. In consequence, the weak‐light detection capacity for this device is enhanced dramatically, which can perceive nighttime low light illuminations with ultrahigh light‐perception sensitivity of 10 2 –10 4 and low power consumption of <10 nW. Leveraging these findings, it is demonstrated that the phototransistor has neuromorphic vision perception behaviors and energy efficiency like human brain under faint light, opening a new opportunity for artificial vision.