Carbon Nanotube-Perovskite Composites for Ultrasensitive Broadband Photodiodes

Organohalide perovskites have gained enormous attentions due to their attractive fundamental properties and easy processing techniques. Recently, halide perovskites have successfully been explored in both broadband and narrowband photodetection devices. However, the inherent large bandgap of most hybrid perovskites has restrained its working wavelength within ultraviolet–visible regime ranging from 300 to 800 nm. Herein, we demonstrate solution-processed composites containing hybrid perovskites and semiconducting single-walled carbon nanotubes as active photoresponsive layers in vertical photodiodes. The resultant diodes perform as ultrasensitive broadband photodetectors extending photoresponse into near-infrared with the detectivity exceeding 3.8 × 1012 Jones and 1.2 × 1012 Jones in the visible and near-infrared regions, respectively, as well as a fast response speed less than 15 μs. The high performance of our photodiodes are attributed to the superior absorption of perovskites and the ultrahigh carrier transfer mobility of single-walled carbon nanotubes and their matched interface. The work offers a novel and promising route for improving carrier transfer with less recombination loss, which would inspire other optoelectronic applications.