Flexible Wire‐Shaped Perovskite Photodetector via Joule Heating for Improved Crystallization and Performance

Abstract

Abstract Organolead triiodide perovskite (CH 3 NH 3 PbI 3 ) is used extensively as the absorber material for both solar cells and photodetectors; however, the reported photodetectors are all planar and flexible planar devices. To the best of knowledge the first flexible wire‐shaped perovskite photodetector is reported. The performance of the wire‐shaped perovskite photodetector on carbon nanotube yarn (CNY) critically depends on the surface geometry and annealing conditions. The use of joule heating method for uniform control of temperature on CNY surface results in smooth perovskite crystalline films, which are used to produce self‐powering photodetectors with strong responsivity (10.2 A W −1 ), detectivity (1.76 × 10 11 J), and I light / I dark (45). This development displays the role of joule heating in the annealing process and demonstrates a cheap, repeatable method for the fabrication of self‐powered perovskite photodetectors.