Bandgap Engineering of Single‐Crystalline Perovskite Arrays for High‐Performance Photodetectors

• Published in: Advanced functional materials Vol. 28; no. 46
• Main Authors: Gao, Hanfei, Feng, Jiangang, Pi, Yueyang, Zhou, Zhonghao, Zhang, Bo, Wu, Yuchen, Wang, Xuedong, Jiang, Xiangyu, Jiang, Lei
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 14.11.2018
• Subjects: Arrays; bandgap engineering; Carrier density; Carrier lifetime; Carrier recombination; Crystal structure; Crystallinity; Crystallization; Crystals; Drying; Materials science; methylaminium lead halides perovskites; Morphology; Nucleation; Optoelectronic devices; optoelectronics; perovskite photodetectors; Perovskites; Photometers; Photonic band gaps; Single crystals; single‐crystalline arrays; Stoichiometry; Thin films
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201804349

Bandgap engineering of single‐crystal lead halide perovskites with remarkable optoelectronic properties, solution processability, and low‐cost nature has been in the forefront of extensive optoelectronic applications. Yet one imminent challenging is to pattern micro‐ and nanostructured perovskite arrays with controlled morphology, precision alignment, and high‐quality single crystallinity owing to the difference of crystallization behaviors between perovskites with diverse halide stoichiometry, leading to the restricted integration of optoelectronic devices. Herein, a facile assembly solution process is developed through cautious regulation, directional dewetting, and microstructured confinement for the nucleation and growth of 1D perovskite single‐crystal arrays with engineered bandgap from 1.7 to 3.1 eV by changing halogen ratios. Photodetectors based on 1D arrays perform a high responsivity of 3.16 × 103 A W−1. In comparison with devices based on perovskite thin film, a notable improvement is achieved owing to the elimination of the carrier recombination in the 1D high‐quality crystalline arrays with the low defect density and long carrier lifetime. This work offers a new insight for the bandgap engineering of patterned single crystals toward the integration of optoelectronic devices. Bandgap engineering of 1D single‐crystal perovskite arrays with precise position, strict alignment, and controllable size is demonstrated through an assembly solution process with controllable dewetting. Photodetectors based on 1D MAPbBr3 arrays are established with a high optoelectronic performance, caused by the eliminated grain boundary, low defect density, and long carrier lifetime of 1D arrays.