Abstract

High-performance phototransistors made fromorganic semiconductor single crystals (OSSCs) have attracted much attention dueto the high responsivity and solution-processing capability of OSSCs. However,OSSC-based phototransistors capable of dual-band spectral response remain adifficult challenge to achieve because organic semiconductors usually possessonly narrow single-band absorption. Here, we report the fabrication ofhigh-performance, dual-band phototransistors from a hybrid structure of a2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT)single-crystal array coated with CH₃NH₃PbI₃ nanoparticles(NPs) synthesized by a simple, one-step solution method. In contrast to C8-BTBTand CH₃NH₃PbI₃ NPs with respectiveabsorption in the ultraviolet (UV) and visible (vis) region, their hybridstructure shows broad absorption covering the entire UV–vis range. Thehybrid-based phototransistors exhibit an ultrahigh responsivity of >1.72 ×10⁴ A/W in the 252–780 nm region, which represents the bestperformance for solution-processing, broadband photodetectors. Moreover,integrated phototransistor circuitries from the hybrid CH₃NH₃PbI₃ NPs/C8-BTBTsingle-crystal array show applications for high-security communication.