Study of CH3NH3PbI2.75Cl0.25photoelectric conversion material based on the first principle

The environment-friendly perovskite solar cell materials CH ₃ NH ₃ PbI _2.75 Cl _0.25 was investigated by using the CASTEP software package in Materials Studio (MS) software. For the CH ₃ NH ₃ PbI ₃ cell, six kinds of the structure and physical properties of the I anion replaced by one Cl anion were built and calculated. Firstly, the geometrical optimization and energy optimization of the six kinds of configurations are obtained by GGA+WC correlation function, and the final optimized geometrical structure and total energy are obtained. Secondly, the geometrical structure of the lowest energy is found, and the structure will be the most stable. The results show that the replacement of I atoms by Cl atoms influences the physical properties of the configuration structure, resulting from the orbit of the contribution of the Cl atoms in the calculation. It can be judged that all the configurations belong to direct semiconductor, and no magnetic moment. In addition, these materials in the low frequency range shows good absorption property, and can be used a good photoelectric conversion material.