Water‐Assisted Size and Shape Control of CsPbBr3 Perovskite Nanocrystals

• Published in: Angewandte Chemie International Edition Vol. 57; no. 13; pp. 3337 - 3342
• Main Authors: Zhang, Xiaoyu, Bai, Xue, Wu, Hua, Zhang, Xiangtong, Sun, Chun, Zhang, Yu, Zhang, Wei, Zheng, Weitao, Yu, William W., Rogach, Andrey L.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 19-03-2018
• Edition: International ed. in English
• Subjects: Chemical synthesis; Crystallization; Crystals; CsPbBr3; Fabrication; light-emitting device; Moisture content; Nanocrystals; Nanotechnology; Nanowires; perovskite nanocrystals; Perovskites; Photoluminescence; Photons; Shape control; water additive; Water content
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201710869

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 CsPbBr3 nanocrystals. The size and the crystallinity, and as a result the band gap tunability of the strongly emitting CsPbBr3 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 CsPbBr3 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−2 and external quantum yield of 1.7 %.
Lead‐halide perovskites are well known to decompose rapidly when exposed to polar solvents. Contrary to this, stable CsPbBr3 nanocrystals could be synthesized through introducing a suitable minor amount of water into the reaction mixture. The size and the crystallinity, and as a result the band gap tunability of the strongly emitting CsPbBr3 nanocrystals correlate with the water content.