Ultrathin and Conformable Lead Halide Perovskite Photodetector Arrays for Potential Application in Retina-Like Vision Sensing

Adv Mater. 2021 Mar;33(9):e2006006. doi: 10.1002/adma.202006006. Epub 2021 Jan 21.

Abstract

Solution-processed lead halide perovskites are considered one of the promising materials for flexible optoelectronics. However, the array integration of ultrathin flexible perovskite photodetectors (PDs) remains a significant challenge limited by the incompatibility of perovskite materials with manufacturing techniques involving polar liquids. Here, an ultrathin (2.4 µm) and conformable perovskite-based PD array (10 × 10 pixels) with ultralight weight (3.12 g m-2 ) and excellent flexibility, is reported. Patterned all-inorganic CsPbBr3 perovskite films with precise pixel position, controllable morphology, and homogenous dimension, are synthesized by a vacuum-assisted drop-casting patterning process as the active layer. The use of waterproof parylene-C film as substrate and encapsulation layer effectively protects the perovskite films against penetration of polar liquids during the peeling-off process. Benefitting from the encapsulation and ultrathin property, the device exhibits long-term stability in the ambient environment, and robust mechanical stability under bending or 50% compressive strain. More importantly, the ultrathin flexible PD arrays conforming to hemispherical support realize imaging of light distribution, indicating the potential applications in retina-like vision sensing.

Keywords: all-inorganic CsPbBr3 perovskite; artificial vision sensing; conformable contact; photodetector arrays; ultrathin photodetectors.