Spray-coated perovskite hemispherical photodetector featuring narrow-band and wide-angle imaging

• Published in: Nature communications Vol. 13; no. 1; p. 6106
• Main Authors: Feng, Xiaopeng, He, Yuhong, Qu, Wei, Song, Jinmei, Pan, Wanting, Tan, Mingrui, Yang, Bai, Wei, Haotong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.10.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005/1007; 639/624/1075/1083; 639/638/298/917; 639/766/1130/2800; Coatings; Crystallization; Film thickness; Flow velocity; Humanities and Social Sciences; I.R. radiation; Imaging; Laboratories; Lead compounds; Light effects; Light emitting diodes; Metal halides; Micrometers; multidisciplinary; Optical paths; Perovskites; Photometers; Photosensitivity; Recognition; Science; Science (multidisciplinary); Single crystals; Spray coating; Substrates; Turbulence models; Wavelength
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-33934-1

Sphere imagers featuring specific wavelength recognition and wide-angle imaging are required to meet the fast development of modern technology. However, it is still challenging to deposit high-quality photosensitive layers on sphere substrates from low-cost solution processes. Here we report spray-coated quasi-two-dimensional phenylethylammonium/formamidinium lead halide (PEA 2 FA n-1 Pb n X 3n+1 ) perovskite hemispherical photodetectors. The crystallization speed is manipulated by perovskite compositions, and the film thickness can be controlled by spray-coating cycles and solution concentration from tens of nanometers to hundreds of micrometers with a fast velocity of 1.28 × 10 −4  cm 3  s −1 . The lens-free hemispherical photodetectors allow light response at a wide incident angle of 180°. Simultaneously, the wavelength selective response from visible to the near-infrared range is achieved with full width at half maximums (FWHMs) of ~20 nm, comparable to single-crystal devices. Wide-angle and wavelength-selective imaging are also demonstrated, which can find potential applications in intelligent recognition and intraoperative navigated surgery. Hemispherical photodetectors allow wide sight angle without the complex optical paths of fisheye lenses. Here, Wei et al, report a spray-coated quasi-two-dimensional perovskite hemispherical photodetector with wavelength selective response from the visible to the near-infrared.