Yu Hongling, Wang Heyong, Zhang Jiangbin, Lu Jun, Yuan Zhongcheng, Xu Weidong, Hultman Lars, Bakulin Artem A, Friend Richard H, Wang Jianpu, Liu Xiao-Ke, Gao Feng
Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, 58183, Sweden.
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
Small. 2019 Feb;15(8):e1804947. doi: 10.1002/smll.201804947. Epub 2019 Jan 28.
Semiconductor quantum dots (QDs) are among the most promising next-generation optoelectronic materials. QDs are generally obtained through either epitaxial or colloidal growth and carry the promise for solution-processed high-performance optoelectronic devices such as light-emitting diodes (LEDs), solar cells, etc. Herein, a straightforward approach to synthesize perovskite QDs and demonstrate their applications in efficient LEDs is reported. The perovskite QDs with controllable crystal sizes and properties are in situ synthesized through one-step spin-coating from perovskite precursor solutions followed by thermal annealing. These perovskite QDs feature size-dependent quantum confinement effect (with readily tunable emissions) and radiative monomolecular recombination. Despite the substantial structural inhomogeneity, the in situ generated perovskite QDs films emit narrow-bandwidth emission and high color stability due to efficient energy transfer between nanostructures that sweeps away the unfavorable disorder effects. Based on these materials, efficient LEDs with external quantum efficiencies up to 11.0% are realized. This makes the technologically appealing in situ approach promising for further development of state-of-the-art LED systems and other optoelectronic devices.
半导体量子点（QDs）是最有前途的下一代光电子材料之一。量子点通常通过外延生长或胶体生长获得，并有望用于溶液处理的高性能光电器件，如发光二极管（LED）、太阳能电池等。在此，报道了一种合成钙钛矿量子点并展示其在高效发光二极管中应用的直接方法。通过从钙钛矿前驱体溶液进行一步旋涂，随后进行热退火，原位合成了具有可控晶体尺寸和性质的钙钛矿量子点。这些钙钛矿量子点具有尺寸依赖的量子限制效应（发射易于调节）和辐射单分子复合。尽管存在大量结构不均匀性，但由于纳米结构之间的有效能量转移消除了不利的无序效应，原位生成的钙钛矿量子点薄膜发出窄带宽发射和高颜色稳定性。基于这些材料，实现了外部量子效率高达11.0%的高效发光二极管。这使得这种具有技术吸引力的原位方法有望用于最先进的发光二极管系统和其他光电器件的进一步发展。
