Multifunctional graphene/organic transistor enabled by polyethyleneimine (PEIE)-induced charge tunneling and trapping effects

Graphene/organic transistors (GOT) hold significant potential for multifunctional bio-inspired optoelectronic applications, integrating sensing, filtering, and neuromorphic processing in a single device. In this study, we demonstrate a GOT based on a graphene/PEIE/bulk heterojunction (BHJ) structure, where the introduction of the PEIE barrier layer induces unique charge tunneling and trap-trapping behaviors of the photo-generated carriers, enabling adaptive switching between memory-free and long-term memory photoresponse under different light conditions. The device can be used for photoplethysmography (PPG) measurement, image preprocessing, and artificial neural network pattern recognition. This work advances bio-inspired optoelectronic devices for intelligent vision and neuromorphic computing applications.