Metal Seeding Growth of Three-Dimensional Perovskite Nanowire Forests for High-Performance Stretchable Photodetectors

Metal halide perovskites have been ubiquitously utilized in both rigid and flexible optoelectronics with high performance. However, developing perovskites-based stretchable optoelectronics is highly challenging because perovskites are intrinsically not stretchable unlike some organic semiconductors. Here, for the first time, we devised a novel metal seeding growth method to obtain three-dimensional (3D) perovskite nanowire forests (NWFs) with excellent mechanical stretchability, akin to the seeding growth of grass in nature. Benefiting from their intrinsic stretchability, perovskite NWFs-based stretchable photodetectors have been demonstrated with excellent photodetection performance. Under 0% strain, the device dark current is as low as 0.18 nA cm-2 at - 2 V bias, contributing to an ultrahigh light-to-dark current ratio (Ilight/Idark) of 1.1 x 105 under 5.5 mW cm-2 illumination. The device also exhibits a high responsivity of 455.3 mA W-1 and specific detectivity of 8.69 x 1012 Jones. Meanwhile, under 80% strain conditions, the device have shown negligible performance drop, especially in the aspect of Ilight/Idark. Our work reports a novel growth process that leads to intriguing 3D perovskite nanostructures with unique mechanical flexibility and stretchability, in addition to high optoelectronic sensing performance. These appealing properties can find applications in high-performance stretchable and wearable optoelectronics in the future.