Faculty of Physics and Technology, Al Farabi Kazakh National University, 71 Al-Farabi Ave., Almaty 050040, Kazakhstan.
Optoelectronics of Disordered Semiconductors, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam-Golm, Germany.
Molecules. 2023 Jan 29;28(3):1288. doi: 10.3390/molecules28031288.
The advantages of IR spectroscopy include relatively fast analysis and sensitivity, which facilitate its wide application in the pharmaceutical, chemical and polymer sectors. Thus, IR spectroscopy provides an excellent opportunity to monitor the degradation and concomitant evolution of the molecular structure within a perovskite layer. As is well-known, one of the main limitations preventing the industrialization of perovskite solar cells is the relatively low resistance to various degradation factors. The aim of this work was to study the degradation of the surface of a perovskite thin film CHNHPbICl caused by atmosphere and light. To study the surface of CHNHPbICl, a scanning electron microscope, infrared (IR) spectroscopy and optical absorption were used. It is shown that the degradation of the functional layer of perovskite proceeds differently depending on the acting factor present in the surrounding atmosphere, whilst the chemical bonds are maintained within the perovskite crystal structure under nitrogen. However, when exposed to an ambient atmosphere, an expansion of the NH band is observed, which is accompanied by a shift in the N-H stretching mode toward higher frequencies; this can be explained by the degradation of the perovskite surface due to hydration. This paper shows that the dissociation of HO molecules under the influence of sunlight can adversely affect the efficiency and stability of the absorbing layer. This work presents an approach to the study of perovskite structural stability with the aim of developing alternative concepts to the fabrication of stable and sustainable perovskite solar cells.
红外（IR）光谱法的优点包括相对较快的分析速度和灵敏度，这使其在制药、化学和聚合物领域得到广泛应用。因此，IR 光谱法为监测钙钛矿层内分子结构的降解及其伴随的演变提供了极好的机会。众所周知，阻碍钙钛矿太阳能电池产业化的主要限制之一是其对各种降解因素的相对低抗性。这项工作的目的是研究 CHNHPbICl 钙钛矿薄膜表面因大气和光照而导致的降解。为了研究 CHNHPbICl 的表面，使用了扫描电子显微镜、红外（IR）光谱法和光吸收法。结果表明，钙钛矿功能层的降解过程因周围大气中存在的作用因素而异，而在氮气中，钙钛矿晶体结构内的化学键得以保持。然而，当暴露于环境大气中时，观察到 NH 带的扩展，同时 N-H 伸缩模式向更高频率移动；这可以通过钙钛矿表面因水合而降解来解释。本文表明，在阳光的影响下，HO 分子的离解会对吸收层的效率和稳定性产生不利影响。这项工作提出了一种研究钙钛矿结构稳定性的方法，旨在开发替代概念以制造稳定和可持续的钙钛矿太阳能电池。
