Vacuum-Drying Processed Micrometer-Thick Stable CsPbBr3 Perovskite Films with Efficient Blue-To-Green Photoconversion

Small. 2019 Aug;15(31):e1901954. doi: 10.1002/smll.201901954. Epub 2019 Jun 13.

Abstract

Metal halide perovskite materials have attracted great attention owing to their fascinating optoelectronic characteristics and low cost fabrication via facile solution processing. One of the potential applications of these materials is to employ them as color-conversion layers (CCLs) for visible blue light to achieve full-color displays. However, obtaining thick perovskite films to realize complete color conversion is a key challenge. Here, the fabrication of micrometer-level thick CsPbBr3 perovskite films is presented through a facile vacuum drying approach. An efficient green photoconversion is realized in a 3.8 µm thick film from blue light @ 463 nm. For a back luminance of 1000 cd m-2 , the brightness of the resulting green emission can reach as high as 200 cd m-2 . Furthermore, only ≈2% of decay in brightness is observed when the films are tested after 18 days of exposure to ambient environment. In addition, a potential design is also proposed for full-color displays with perovskite materials incorporated as CCLs.

Keywords: color conversion; perovskites; photoconversion; vacuum drying.