Enhanced Stability and Optical Absorption in the Perovskite‐Based Compounds MA1−xCsxPbI3−yBry. Issue 3 (11th January 2019)

• Record Type: Journal Article
• Authors: Chang, Junli; Yuan, Hongkuan; Wang, Biao; Huang, Yuhong; Chen, Xiaorui; Chen, Hong
• Is Part Of: Chemphyschem. Volume 20:Issue 3(2019)
• Page Start: 489
• Page End: 498
• Publication Date: 2019-01-11
• Subjects: perovskite compounds -- optical absorption -- stability -- first-principles calculations; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201800927
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Organometal halide perovskites have been outstanding from enormous amount of functional materials thanks to their highly cost‐effective processability and prominent light harvesting capacity. Unfortunately, poor long‐term stability seriously hinders their further development. The recent experimental observations suggest that Cesium is a promising candidate to enhance the stability of MAPbI3 . To explore the inherent mechanism, a first‐principles investigation based on density functional theory, including hybrid functional, has been performed to analyze the electronic and optical properties of perovskite series MA0.75 Cs0.25 PbI3− y Br y . The results indicate that perovskite compound MA0.75 Cs0.25 PbI2 Br is significantly superior to the other doped series in terms of optical absorption within the visible‐light range. In the meanwhile, both Bader charge analysis and charge density distribution show that the compound of MA0.75 Cs0.25 PbI2 Br is the most stable among all the doped perovskite series. Moreover, it is clearly manifested that the impact of cesium is mainly embodied in the enhancement of the stability rather than in the improvement of optical absorption. Our study sheds a new light on screening new‐type light harvesting materials, and provides theoretical insight into the rationale design of highly efficient and stable photovoltaic devices based on these functional materials. Abstract : Show me your inherence : Theoretical insights into electronic and optical properties of perovskite compounds MA0.75 Cs0.25 PbI3− y Br y are presented, including geometric structure, density of state, charge density distribution and absorption spectra; explaining that the stability of perovskite compounds is significantly enhanced via Cs doping, while the optical absorption is slightly improved.