Due to its unique optoelectronic properties, non-toxic tin based perovskite has become an emerging candidate material for efficient near-infrared LEDs. However, the easy oxidation of Sn2+and the rapid crystallization rate of tin based perovskite lead to unsatisfactory film quality, resulting in lower efficiency of tin based perovskite light-emitting diodes (Pero LEDs).
In this study, Wei Zhanhua and others from Overseas Chinese University investigated the effect of commonly used solvents on the quality of CsSnI3 films. It is worth noting that DMSO exhibits a stronger interaction with SnI2, forming a stable SnI2 · 3DMSO intermediate phase. This intermediate effectively inhibits the oxidation of Sn2+, slows down the crystallization rate, and results in a lower defect density and higher photoluminescence quantum yield of the prepared perovskite thin film. Therefore, the corresponding Pero LED achieved a maximum external quantum efficiency (EQE) of 5.6%, making it one of the most efficient near-infrared Pero Sn LEDs.
In addition, the device also has the characteristics of ultra-low efficiency roll down and high reproducibility. This study emphasizes the crucial role of solvent perovskite coordination in determining the quality of thin films. These findings provide valuable guidance for solvent screening in the preparation of efficient and stable tin based perovskites.
Li Y, Guan X, Meng Y, et al. Boosting CsSnI3-based near-infrared perovskite light-emitting diodes performance via solvent coordination engineering. InfoMat. 2024;e12537.
DOI:10.1002/inf2.12537
https://onlinelibrary.wiley.com/doi/full/10.1002/inf2.12537