Hong Daocheng, Zhang Yuchen, Pan Shuhan, Liu Hanyu, Mao Wei, Lu Zhenda, Tian Yuxi
Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng, Jiangsu224051, China.
Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu210023, China.
J Phys Chem Lett. 2022 Nov 24;13(46):10751-10758. doi: 10.1021/acs.jpclett.2c03159. Epub 2022 Nov 14.
All-inorganic metal halide perovskite nanocrystals (NCs) have been exceptional candidates for high-performance solution-processed optoelectronic and photonic devices compared with organometal halide perovskite NCs due to their superior stability. However, the interactions between all-inorganic perovskite NCs and moisture, which is an acknowledged detrimental factor, are still under debate, and detailed investigations to uncover such fundamentals remain to be performed. Herein, with wide-field fluorescence microscopy, the burst photoluminescence blinking responses of CsPbBr NCs were observed in ambient air, and moisture rather than oxygen was verified to be the key factor that leads to the enhanced PL intensity and reduced OFF duration. This behavior is rationalized through an effective passivation effect of the adsorbed water molecules on the surface halide vacancies on CsPbBr NCs. This work validates that ∼40% humidity atmospheres are helpful for better utilizing the all-inorganic perovskites, which is evidence of their promising prospect for application.
与有机金属卤化物钙钛矿纳米晶体相比，全无机金属卤化物钙钛矿纳米晶体（NCs）因其卓越的稳定性，一直是高性能溶液处理光电器件和光子器件的理想候选材料。然而，全无机钙钛矿纳米晶体与水分之间的相互作用（水分是公认的有害因素）仍存在争议，揭示此类基本原理的详细研究仍有待开展。在此，利用宽场荧光显微镜，在环境空气中观察到了CsPbBr纳米晶体的突发光致发光闪烁响应，并且证实水分而非氧气是导致光致发光强度增强和关闭持续时间缩短的关键因素。通过吸附水分子对CsPbBr纳米晶体表面卤化物空位的有效钝化作用，解释了这种行为。这项工作证实，约40%湿度的大气有助于更好地利用全无机钙钛矿，这证明了它们具有广阔的应用前景。
