Physical Sciences and Engineering Division , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia.
Department of Physics, College of Sciences , Princess Nourah bint Abdulrahman University (PNU) , Riyadh 11671 , Saudi Arabia.
ACS Appl Mater Interfaces. 2019 Feb 6;11(5):5223-5231. doi: 10.1021/acsami.8b17249. Epub 2019 Jan 25.
All-inorganic lead halide perovskites are promising materials for many optoelectronic applications. However, two issues that arise during device fabrication hinder their practical use, namely, inadequate continuity of coated inorganic perovskite films across large areas and inability to integrate these films with traditional photolithography due to poor adhesion to wafers. Herein, for the first time, to address these issues, we show a room-temperature synthesis process employed to produce CsPbBr perovskite nanocrystals with two-dimensional (2D) nanosheet features. Due to the unique properties of these 2D nanocrystals, including the "self-assembly" characteristic, the "double solvent evaporation inducing self-patterning" strategy is used to generate high-quality patterned thin films in selected areas automatically after drop-casting, enabling fabrication of high-performance devices without using complex and expensive fabrication processing techniques. The films are free from microcracks. In a proof-of-concept experiment, photodetector arrays are used to demonstrate the superior properties of such films. We provide evidence of both high responsivity (9.04 A/W) and high stability across large areas. The photodetectors fabricated on a flexible substrate exhibit outstanding photoresponse stability. Advanced optical and structural studies reveal the possible mechanism. Our simple and cost-effective method paves the way for the next-generation nanotechnology based on high-performance, cost-effective optoelectronic devices.
全无机卤化铅钙钛矿是许多光电应用的有前途的材料。然而，器件制造过程中出现的两个问题阻碍了它们的实际应用，即涂覆的无机钙钛矿薄膜在大面积上的连续性不足，以及由于与晶圆的附着力差而无法与传统光刻技术集成。在此，我们首次展示了一种室温合成工艺，用于生产具有二维（2D）纳米片特征的 CsPbBr 钙钛矿纳米晶体。由于这些 2D 纳米晶体的独特性质，包括“自组装”特性，因此使用“双溶剂蒸发诱导自图案化”策略在滴铸后自动在选定区域生成高质量的图案化薄膜，从而无需使用复杂且昂贵的制造工艺技术来制造高性能器件。这些薄膜没有微裂纹。在概念验证实验中，使用光电探测器阵列证明了这些薄膜的优越性能。我们提供了大面积高响应性（9.04 A/W）和高稳定性的证据。在柔性衬底上制造的光电探测器表现出出色的光响应稳定性。先进的光学和结构研究揭示了可能的机制。我们的简单且具有成本效益的方法为基于高性能、低成本光电设备的下一代纳米技术铺平了道路。
