High-Performance Organic Phototransistors Enabled by Vertical Phase Separation-Induced Nano-Interpenetrating Heterojunctions

Organic phototransistors (OPTs) have broad application prospects in wearable electronics, health monitoring, retinal imaging, and other fields due to their flexibility, solution processing, and large-area preparation advantages. However, traditional planar heterostructures and bulk heterojunctions have limitations in separating and transporting photogenerated carriers, which affects the performance of organic phototransistors. Here, a vertical phase separation-induced nano-interpenetrating heterostructure (VHJ) is proposed. The formed nano-interpenetrating network can provide more interfaces to facilitate exciton dissociation, and the structure does not affect carrier transport in the conducting channel. Specifically, due to the balance between light absorption and carrier transport, the photosensitivity (P) of OPTs reaches 7.76 × 104. This provides a new perspective for exploring more effective preparation methods and structural design to prepare high-performance OPTs.