Schmitz Fabian, Neisius Raphael, Horn Jonas, Sann Joachim, Schlettwein Derck, Gerhard Marina, Gatti Teresa
Institute of Physical Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.
Center for Materials Research, Justus Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.
Nanotechnology. 2022 Mar 4;33(21). doi: 10.1088/1361-6528/ac54df.
Silver-bismuth double perovskites are promising replacement materials for lead-based ones in photovoltaic (PV) devices due to the lower toxicity and enhanced stability to environmental factors. In addition, they might even be more suitable for indoor PV, due to the size of their bandgap better matching white LEDs emission. Unfortunately, their optoelectronic performance does not reach that of the lead-based counterparts, because of the indirect nature of the band gap and the high exciton binding energy. One strategy to improve the electronic properties is the dimensional reduction from the 3D to the 2D perovskite structure, which features a direct band gap, as it has been reported for 2D monolayer derivates of CsAgBiBrobtained by substituting Cscations with bulky alkylammonium cations. However, a similar dimensional reduction also brings to a band gap opening, limiting light absorption in the visible. In this work, we report on the achievement of a bathochromic shift in the absorption features of a butylammonium-based silver-bismuth bromide monolayer double perovskite through doping with iodide and study the optical properties and stability of the resulting thin films in environmental conditions. These species might constitute the starting point to design future sustainable materials to implement as active components in indoor photovoltaic devices used to power the IoT.
由于毒性较低且对环境因素的稳定性增强，银铋双钙钛矿有望成为光伏（PV）器件中铅基材料的替代材料。此外，由于其带隙大小与白色发光二极管（LED）发射更好匹配，它们甚至可能更适合用于室内光伏。不幸的是，由于带隙的间接性质和高激子结合能，它们的光电性能无法达到铅基同类材料的水平。一种改善电子性能的策略是将结构从三维（3D）钙钛矿降至二维（2D）钙钛矿结构，这种结构具有直接带隙，正如通过用庞大的烷基铵阳离子取代铯阳离子获得的二维单层铯银铋溴化物衍生物所报道的那样。然而，类似的维度降低也会导致带隙打开，限制可见光吸收。在这项工作中，我们报告了通过碘化物掺杂实现基于丁基铵的溴化银铋单层双钙钛矿吸收特征的红移，并研究了所得薄膜在环境条件下的光学性质和稳定性。这些材料可能构成设计未来可持续材料的起点，以用作物联网供电的室内光伏器件中的活性组件。
