High-performance stretchable photodetector based on CH₃NH₃PbI₃ microwires and graphene

A stretchable photodetector was fabricated by releasing a prestrained 3 M very high bond (VHB) substrate coated with perovskite CH₃NH₃PbI₃ microwires and graphene. The light harvesting CH₃NH₃PbI₃ microwires were realized through a transformation from CH₃NH₃PbI₃ bulk single crystals. Graphene served as an expressway for photoinduced carriers in the perovskite. Under a very low working voltage bias of 0.01 V and irradiance power of 13.5 mW cm^-2 under 785 nm laser illumination, the responsivity could be as high as 2.2 mA W^-1. When the device was stretched up to 30%, 50%, and 80% strain, the responsivity was maintained at 0.96, 0.60, and 0.21 mA W^-1, respectively. It also showed a fast photoresponse (<0.12 s) after stretching to 10%, 30%, 50%, 80%, and even to 100%. The device performed well after 100 cycles of stretching to 50% strain.