Selective Solar‐Blind UV Monitoring Based on Organic Field‐Effect Transistor Nonvolatile Memories

Ultraviolet (UV) monitoring has wide applications in diverse fields, where sensitive photodetection and recording of UV exposure history are often simultaneously required. A new strategy is herein developed to achieve solar‐blind UV monitoring. Based on organic field‐effect transistors (OFETs), nonvolatile memories with both p‐type or n‐type organic active layers demonstrate selective and storable UV response. These OFET memories are sensitive only to solar‐blind UV light of 254 nm, and have no response to UV light of 365 nm or visible light. The photoresponsive signal can be recorded in a nonvolatile manner with excellent retention and rewritable capability, which integrates solar‐blind UV detection and memory into a single device. These OFET memories are well compatible with flexible substrates, and thus could be very useful for portable and/or wearable UV dosimetry. The conventional bandgap photoexcitation mechanism is not applicable to the this case, and a UV‐induced interfacial excitation mechanism is proposed to interpret the device features.