Energy level matched by an external electric field in nontoxic halide perovskite CH3NH3SnI3

To solve the energy level matching problem of the hybrid perovskite CH3NH3SnI3 with a band gap of 1.3 eV, we investigate the key role of an externally applied electric field. First-principle calculations were performed to determine the physical properties of this material under an external electric field. Based on the results, it was determined that the additional energy supplied by the electric field can increase the cell volume and induce structural distortion of hybrid perovskites. The electric field reduced the band gap of CH3NH3SnI3. In addition, the Fermi level, valence band maximum and conduction band minimum were adjusted to match the energies level of the transport layers. Specifically, we outline the physical mechanism of band structure reconstitution induced by the Stark effect.