Flexible and air-stable perovskite network photodetectors based on CH3NH3PbI3/C8BTBT bulk heterojunction

Flexible perovskite network photodetectors based on the bulk heterojunction (BHJ) of CH₃NH₃PbI₃ and an organic semiconductor dioctylbenzothieno [2,3-b] benzothiophene (C8BTBT) have been fabricated via a simple, one-step solution process. The responsivity, detectivity, and response time as the critical parameters of CH₃NH₃PbI₃/C8BTBT BHJ network photodetectors reach 8.1 AW^-1, 2.17 × 10¹² Jones, and 7.1 ms, respectively. Meanwhile, they can maintain over 70% of original performance even when exposed to ambient conditions (humidity ∼ 45%) for 50 days without encapsulation. Furthermore, the CH₃NH₃PbI₃/C8BTBT BHJ network photodetectors fabricated on a polyethylene terephthalate (PET) substrate exhibit superior flexibility at different bending radii and large numbers of bending cycles. The photocurrent just shows a decrease of less than 5% as the devices are bent for 10 000 cycles at a small radius of 7.5 mm. The present research indicates that BHJ networks composed of perovskites and organic semiconductors open up the exciting opportunity for fabricating high-performance, low-cost, flexible electronic and optoelectronic devices.