State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun, 130012, China.
Department of Materials Science, Key Laboratory of Mobile Materials MOE, State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, 130012, China.
Angew Chem Int Ed Engl. 2018 Mar 19;57(13):3337-3342. doi: 10.1002/anie.201710869. Epub 2018 Feb 23.
Lead-halide perovskites are well known to decompose rapidly when exposed to polar solvents, such as water. Contrary to this common-place observation, we have found that through introducing a suitable minor amount of water into the reaction mixture, we can synthesize stable CsPbBr nanocrystals. The size and the crystallinity, and as a result the band gap tunability of the strongly emitting CsPbBr nanocrystals correlate with the water content. Suitable amounts of water change the crystallization environment, inducing the formation of differently shaped perovskites, namely spherical NCs, rectangular nanoplatelets, or nanowires. Bright CsPbBr nanocrystals with the photoluminescence quantum yield reaching 90 % were employed for fabrication of inverted hybrid inorganic/organic light-emitting devices, with the peak luminance of 4428 cd m and external quantum yield of 1.7 %.
卤化铅钙钛矿在暴露于极性溶剂（如水）时会迅速分解，这是众所周知的。与这一常见观察结果相反，我们发现通过在反应混合物中引入适量的水，可以合成稳定的 CsPbBr 纳米晶体。强发光 CsPbBr 纳米晶体的尺寸、结晶度以及带隙可调谐性与含水量有关。适量的水会改变结晶环境，从而诱导形成不同形状的钙钛矿，即球形 NCs、矩形纳米薄片或纳米线。具有高达 90%的光致发光量子产率的亮 CsPbBr 纳米晶体被用于制造倒置混合无机/有机发光器件，其峰值亮度为 4428 cd/m，外量子效率为 1.7%。
