2020 年 45 巻 3 号 p. 67-71
The Σ5(210)/[001] grain boundary (GB) of methyl-ammonium lead triiodide (MAPbI3) perovskite, one of the high-symmetry coincident site boundaries, is characterized by density functional theory. We searched for the lowest energy GB structure through ab-initio atomistic relaxation of symmetric twin boundaries with and without translational shifts relative to the GB plane. We confirmed that the symmetric Σ5(210)/[001] GB of MAPbI3 perovskite is the most stable among all the structures examined. The electronic density of states of the GB structure reveals no gap states. The electronic states of the valence-band maximum and conduction-band minimum are mainly p orbitals of I and Pb atoms, respectively.