Large-Scale Single-Crystal Organic Semiconductor/Graphene Heterojunctions for High-Performance Phototransistor Arrays

Two-dimensional (2D) organic-inorganic van der Waals heterojunctions (vdWHs) are promising for integrated optoelectronics, but scalable fabrication of highly crystalline heterostructures with clean interfaces remains challenging. Here, we report centimeter-scale organic-inorganic vdWHs assembled by combining wet transfer of monolayer graphene with air-liquid interfacial growth of single-crystal C6-DPA. The resulting C6-DPA/graphene phototransistor exhibits broadband photodetection from 365 to 808 nm at room temperature, delivering a responsivity of 1.06 × 106 A W-1, a detectivity of 8.42 × 1015 Jones, and rise/decay times of 7.81/52.3 ms under 450 nm illumination. Large-area phototransistor arrays fabricated from a single heterojunction show excellent uniformity, near-unity yield, and high-contrast imaging capability. This work establishes a scalable route to large-area, highly crystalline organic-inorganic vdWHs and highlights their potential for high-performance integrated optoelectronic systems.