Reshuffling of Electronic Environment by Introducing CH3NH2F+ as an Organic Cation for Enhanced Power Conversion Efficiency and Stability of the Designed Hybrid Organic–Inorganic Perovskite

• Published in: Journal of physical chemistry. C 2019-06, Vol.123 (22), p.13385-13393
• Main Authors: Kumar, Aditya, Singh, Ajeet, Ojha, Animesh K
• Format: Article
• Language: English
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.9b00050

A suitable substitution of the organic cation in hybrid organic–inorganic perovskite is an effective approach to tune carrier concentration, electronic structure, band gap, and optical absorption. Immense research efforts have been made to find perovskite with enhanced stability, red shift with high absorption yield, and better charge-transport properties. Presently, a new perovskite CH3NH2FPbI3 has shown relatively improved properties in terms of structural stability, band gap, red-shifted absorption with high yield, and optical properties compared to CH3NH3PbI3 (MAPbI3). It infers that the CH3NH2FPbI3 may be a better option for perovskite solor cell. The reaction enthalpy of CH3NH2FPbI3 turns out to be −1.6 eV. It indicates that the designed perovskite is more stable compared to MAPbI3. The calculated partial density of states and electron localization functions revealed electronic coupling between organic and inorganic networks of CH3NH2FPbI3. The enhanced hydrogen-bond interaction between the cation and inorganic network modifies the covalent/ionic character of Pb–I bonds. The increased octahedral tilting in CH3NH2FPbI3 compared to MAPbI3 improves its optical properties significantly. The calculated results demonstrate that the strength of the hydrogen bond can be used as an additional control parameter to optimize the photovoltaic properties and structural stability of perovskites.