Modulation of strain, electric field and organic cation rotation on the band gap and electronic structures of organic-inorganic hybrid perovskite CH3NH3PbI3

摘要

Band gap modulation engineering is an important step in the application of optoelectronic materials. In this paper, the first-principles calculations were carried out to study the influence of strain, external electric field, spatial orientation of organic cation on the band gaps and electronic structures of organic-inorganic hybrid halide perovskites CH3NH3PbI3. The results show that both the uniform strain and the tetragonal deformation can modulate the band gap obviously. The electric field of 0.2 V/angstrom is the critical point of the band gap modulation. The band gap increases when an electric field is applied from 0 to 0.2 V/angstrom. The electric field above 0.2 V/angstrom. will cause the band gap to decrease. The spatial orientation of the organic cation also has modulation influence on the band gap of CH3NH3PbI3, but has no effect on the direct semiconductor characteristics. The above results will be helpful to study the band gap modulation of other organic-inorganic hybrid halide perovskites.