Chen Jianni, Wu Haixia, Huang Yaqian, Xu Jisheng, Lu Xinye, Zhou Wendi, Song Jie, Huang Rui
School of Materials Science and Engineering, Hanshan Normal University, Chaozhou 521041, China.
Materials (Basel). 2023 Sep 20;16(18):6309. doi: 10.3390/ma16186309.
Zero-dimensional (0D) tin halide perovskites, characterized by their broadband and adjustable emissions, high photoluminescence quantum yield, and absence of self-absorption, are crucial for the fabrication of high-efficiency optoelectronic devices, such as LEDs, solar cells, and sensors. Despite these attributes, boosting their emission efficiency and stability poses a significant challenge. In this work, Cr-doped CsSnBrF perovskites were synthesized using a water-assisted wet ball-milling method. The effect of CrF addition on photoluminescence properties of CsSnBrF Perovskites was investigated. We found that Cr-doped CsSnBrF Perovskites exhibit a broad emission band, a substantial Stokes shift, and an efficient green light emission centered at about 525 nm at ambient temperature. The derived photoluminescence quantum yield amounted to as high as 56.3%. In addition, these Cr-doped CsSnBrF perovskites outperform their undoped counterparts in terms of thermal stability. Through a comprehensive analysis of photoluminescence measurements, our findings suggested that the elevated photoluminescence quantum yield can be attributed to the enhanced exciton binding energy of self-trapped excitons (STEs) and the suitable electron-phonon coupling resulting from the substantial distortion of [SnBr] octahedra instigated by the addition of CrF.
零维（0D）卤化锡钙钛矿具有宽带可调发射、高光致发光量子产率和无自吸收等特性，对于制造高效光电器件（如发光二极管、太阳能电池和传感器）至关重要。尽管具有这些特性，但提高它们的发射效率和稳定性仍面临重大挑战。在这项工作中，采用水辅助湿球磨法合成了Cr掺杂的CsSnBrF钙钛矿。研究了CrF添加量对CsSnBrF钙钛矿光致发光性能的影响。我们发现，Cr掺杂的CsSnBrF钙钛矿在室温下表现出宽发射带、大斯托克斯位移和以约为525nm为中心的高效绿色发光。推导得到的光致发光量子产率高达56.3%。此外，这些Cr掺杂的CsSnBrF钙钛矿在热稳定性方面优于未掺杂的同类材料。通过对光致发光测量的综合分析，我们的研究结果表明，光致发光量子产率提高可归因于自陷激子（STE）的激子结合能增强以及由于添加CrF导致[SnBr]八面体大量畸变而产生的合适的电子-声子耦合。
