Key Words:Lead compounds;Blue shift - Bromine compounds - Defects - Film preparation - Light emitting diodes - Perovskite - Perovskite solar cells - Photodetectors - Photons - Thin films
Abstract:All-inorganic lead halide perovskite CsPbBr<inf>3</inf> has important applications in photoelectronic devices such as photodetectors, LEDs and photovoltaic devices. However, preparing high-quality CsPbBr<inf>3</inf> thin films has proven to be challenging. In this study, we prepared all-inorganic lead halide perovskite CsPbBr<inf>3</inf> thin films with micron-grains (MG-CsPbBr<inf>3</inf>-TF) via a heat-spraying process (HSP) using a CsPbBr<inf>3</inf>-saturated solution (CsPbBr<inf>3</inf>-SS), and the films exhibited large area, low defects and high stability. The grain size of MG-CsPbBr<inf>3</inf>-TF was about 1-5 microns. The micron-sized grains in MG-CsPbBr<inf>3</inf>-TF enabled the absorption cutoff edge to be extended from 537 to 545 nm. In addition, the presence of fewer boundaries in MG-CsPbBr<inf>3</inf>-TF reduced the defects in MG-CsPbBr<inf>3</inf>-TF (the blue shift of luminescence). The response wavelengths of a low-cost and self-driven (zero-biased) photodetector based on MG-CsPbBr<inf>3</inf>-TF were from 330 to 600 nm. CsPbBr<inf>3</inf> thin films having a large area (10 cm × 10 cm) and micron-sized grains were also prepared by HSP and exhibited excellent stability (1944 h) in air (T = 298 K, 40% humidity). To the best of our knowledge, this is the first study of high-quality CsPbBr<inf>3</inf> thin films prepared by HSP. The results are of great interest for both fundamental research and practical applications of CsPbBr<inf>3</inf> in photodetectors, LEDs and photovoltaic devices.<br/> © 2018 The Royal Society of Chemistry.
Volume:8
Issue:51
Translation or Not:no