锡
密度泛函理论
发光
钙钛矿(结构)
纳米晶
化学
卤化物
纳米技术
量子产额
化学物理
材料科学
无机化学
计算化学
结晶学
光电子学
有机化学
物理
荧光
量子力学
作者
Qi Liu,Jun Yin,Bin-Bin Zhang,Jia-Kai Chen,Yang Zhou,Lu-Min Zhang,Luming Wang,Qing Zhao,Jingshan Hou,Jie Shu,Bo Song,Naoto Shirahata,Osman M. Bakr,Omar F. Mohammed,Hongtao Sun
摘要
The synthesis of highly luminescent colloidal CsSnX3 (X = halogen) perovskite nanocrystals (NCs) remains a long-standing challenge due to the lack of a fundamental understanding of how to rationally suppress the formation of structural defects that significantly influence the radiative carrier recombination processes. Here, we develop a theory-guided, general synthetic concept for highly luminescent CsSnX3 NCs. Guided by density functional theory calculations and molecular dynamics simulations, we predict that, although there is an opposing trend in the chemical potential-dependent formation energies of various defects, highly luminescent CsSnI3 NCs with narrow emission could be obtained through decreasing the density of tin vacancies. We then develop a colloidal synthesis strategy that allows for rational fine-tuning of the reactant ratio in a wide range but still leads to the formation of CsSnI3 NCs. By judiciously adopting a tin-rich reaction condition, we obtain narrow-band-emissive CsSnI3 NCs with a record emission quantum yield of 18.4%, which is over 50 times larger than those previously reported. Systematic surface-state characterizations reveal that these NCs possess a Cs/I-lean surface and are capped with a low density of organic ligands, making them an excellent candidate for optoelectronic devices without any postsynthesis ligand management. We showcase the generalizability of our concept by further demonstrating the synthesis of highly luminescent CsSnI2.5Br0.5 and CsSnI2.25Br0.75 NCs. Our findings not only highlight the value of computation in guiding the synthesis of high-quality colloidal perovskite NCs but also could stimulate intense efforts on tin-based perovskite NCs and accelerate their potential applications in a range of high-performance optoelectronic devices.
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