Fine‐Tuning Single‐Source White‐Light Emission from All‐Inorganic Corrugated 2D Antimony‐Halide Perovskite
Fei Xu, Xiang Wang, Yue Li, Beng Jiang, Zuoru Dong, Zichen Yang, Jiaxing Kang, Xin Shu, Zuimin Jiang, Feng Hong, Run Xu, Zhongquan Ma, Teng Chen, Zhan Xu, Haitao Xu
Abstract
Abstract Corrugated 2D antimony‐halide perovskites such as Cs 3 Sb 2 Cl 9 (CSC) are promising candidates for single‐source white‐light emission due to their ultra‐broadband spectra. However, CSC has a serious luminescence quenching phenomenon due to inadequate confinement of excitons. By the homovalent substitution of trivalent antimony cation Sb 3+ by a small amount of trivalent rare earth (RE) cations RE 3+ , the photoluminescence intensities from high‐quality Cs 3 (Sb 1− x RE x ) 2 Cl 9 (CSRC) (RE = Ce, Sm, Nd, Y, Er, etc.) films at room temperature (RT) are over two orders of magnitude higher than that of CSC film. Especially, the photoluminescence quantum yield (PLQY) for the Cs 3 (Sb 0.995 Er 0.005 ) 2 Cl 9 film is 9.5% at RT, which is much higher than A 3 B 2 X 9 perovskites previously reported for single‐source white‐light lighting. Furthermore, the Cs 3 (Sb 0.995 Er 0.005 ) 2 Cl 9 film exhibits an ultra‐broadband emission with the full width at half maximum reaching 554 meV at RT, resulting in a “warm” white‐light with the CIE coordinate (0.33, 0.46) and the correlated color temperature of 5450 K. The PLQY enhancement can be considered as the fact that a high activation energy by bandgap widening effect and Type‐I‐like “straddling” band alignment between Cs 3 Sb 2 Cl 9 and Cs 3 Er 2 Cl 9 lead to reducing nonradiative losses and increasing radiative recombination channels. Meanwhile, the spectral broadening can be considered to be attributed to strong effect of electron–phonon interaction.