Tian Shun, Li Guixiang, Turnell-Ritson Roland C, Fei Zhaofu, Bornet Aurélien, Nazeeruddin Mohammad Khaja, Dyson Paul J
Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
Angew Chem Int Ed Engl. 2024 Aug 5;63(32):e202407193. doi: 10.1002/anie.202407193. Epub 2024 Jul 3.
As a leading contender to replace lead halide perovskites, tin-based perovskites have demonstrated ever increasing performance in solar cells and light-emitting diodes (LEDs). They tend to be processed with dimethyl sulfoxide (DMSO) solvent, which has been identified as a major contributor to the Sn(II) oxidation during film fabrication, posing a challenge to the further improvement of Sn-based perovskites. Herein, we use NMR spectroscopy to investigate the kinetics of the oxidation of SnI, revealing that autoamplification takes place, accelerating the oxidation as the reaction progresses. We propose a mechanism consistent with these observations involving water participation and HI generation. Building upon these insights, we have developed low-temperature Sn-based perovskite LEDs (PeLEDs) processed at 60 °C, achieving enhanced external quantum efficiencies (EQEs). Our research underscores the substantial potential of low-temperature DMSO solvent processes and DMSO-free solvent systems for fabricating oxidation-free Sn-based perovskites, shaping the future direction in processing Sn-containing perovskite materials and optoelectronic devices.
作为取代铅卤化物钙钛矿的主要竞争者，锡基钙钛矿在太阳能电池和发光二极管（LED）中表现出不断提高的性能。它们通常使用二甲基亚砜（DMSO）溶剂进行处理，该溶剂已被确定为薄膜制造过程中Sn（II）氧化的主要促成因素，这对锡基钙钛矿的进一步改进构成了挑战。在此，我们使用核磁共振光谱研究SnI氧化的动力学，揭示了自放大现象的发生，随着反应的进行加速了氧化。我们提出了一种与这些观察结果一致的机制，涉及水的参与和HI的生成。基于这些见解，我们开发了在60°C下处理的低温锡基钙钛矿发光二极管（PeLED），实现了更高的外量子效率（EQE）。我们的研究强调了低温DMSO溶剂工艺和无DMSO溶剂体系在制造无氧化锡基钙钛矿方面的巨大潜力，为含锡钙钛矿材料和光电器件的加工指明了未来方向。
