Huang Pei-Chen, Yang Ting-Jia, Lin Chia-Jou, Wang Man-Ying, Lin Wei-Chun
Department of Photonics, National Sun Yat-sen University, Kaohsiung City 80424, Taiwan (R.O.C.).
Langmuir. 2024 Jun 11;40(23):11873-11887. doi: 10.1021/acs.langmuir.3c03816. Epub 2024 May 23.
In recent years, organic-inorganic hybrid perovskite materials have become one of the most promising materials in the new generation of solar cells. These perovskites can provide excellent photoelectric properties after a simple fabrication process. Although perovskite solar cells have achieved high power conversion efficiency, instability concerns regarding material exposure to heat, moisture, air, and UV light present hindrances to commercialization. In this study, three kinds of perovskites (MAPbI, MAPbIBr, and MAPbICl) were used to investigate the crystal stability upon exposure to heat and UV light. SEM, XRD, and FTIR were used to observe the surface morphology, crystal structure, and functional groups of the perovskite thin films. XPS was used to examine the surface composition and chemical state of the perovskite thin films under different conditions. Among these three types of perovskites, it was found that the MAPbIBr crystal demonstrated the best stability. ToF-SIMS was used to confirm the molecular distribution of the MAPbIBr films upon exposure to heat and UV light at different depths. ToF-SIMS revealed that [Pb] and [PbI] aggregated at the interface between the perovskite and ITO substrate after 14 days of thermal treatment. On the other hand, [Pb] and [PbI] were distributed uniformly after 3 days of UV exposure. This study systematically analyzed and revealed the thermal- and UV-induced degradation process of three perovskite films by using surface analysis techniques. It was concluded that bromine-doped perovskite films had better stability, and UV light caused more severe damage than heat.
近年来，有机-无机杂化钙钛矿材料已成为新一代太阳能电池中最具潜力的材料之一。经过简单的制备工艺，这些钙钛矿就能具备优异的光电性能。尽管钙钛矿太阳能电池已实现了高功率转换效率，但材料暴露于热、湿气、空气和紫外光下时的不稳定性问题，给商业化带来了阻碍。在本研究中，使用了三种钙钛矿（MAPbI、MAPbIBr和MAPbICl）来研究其在热和紫外光作用下的晶体稳定性。利用扫描电子显微镜（SEM）、X射线衍射仪（XRD）和傅里叶变换红外光谱仪（FTIR）来观察钙钛矿薄膜的表面形貌、晶体结构和官能团。使用X射线光电子能谱仪（XPS）来检测不同条件下钙钛矿薄膜的表面组成和化学状态。在这三种类型的钙钛矿中，发现MAPbIBr晶体表现出最佳的稳定性。使用飞行时间二次离子质谱仪（ToF-SIMS）来确认MAPbIBr薄膜在不同深度下经热和紫外光照射后的分子分布。ToF-SIMS显示，经过14天热处理后，[Pb]和[PbI]在钙钛矿与氧化铟锡（ITO）衬底的界面处聚集。另一方面，在紫外光照射3天后，[Pb]和[PbI]均匀分布。本研究通过表面分析技术系统地分析并揭示了三种钙钛矿薄膜的热致和紫外光致降解过程。得出的结论是，溴掺杂的钙钛矿薄膜具有更好的稳定性，且紫外光造成的损伤比热更严重。
