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

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.