Computed and Experimental Absorption Spectra of the Perovskite CH3NH3PbI3

作者：Zhu Xi; Su Haibin^*; Marcus Rudolph A; Michel Beyerle Maria E

来源：Journal of Physical Chemistry Letters, 2014, 5(17): 3061-3065.

DOI：10.1021/jz501174e

Electronic structure and light absorption properties of the perovskite CH3NH3PbI3 are investigated by relativistic density functional theory with quasiparticle GW corrections and many-body interactions. The nature of the Wannier exciton is studied by solving the Bethe-Salpeter equation augmented with the analysis of a conceptual hydrogenlike model. The computed absorption spectrum unravels a remarkable absorption %26quot;gap%26quot; between the first two absorption peaks. This discontinuity is maintained in the calculated tetragonal structure that, however, is not stable at low temperature. Most importantly, the discontinuity is also observed in the experimental absorption spectrum of the orthorhombic single crystal at low temperature (4 K). However, in contrast to the single crystal, in a polycrystalline perovskite film at 5 K the %26quot;gap%26quot; is filled by a monotonously increasing absorption throughout the visible range. This feature of thin films points to the potential significance of defect absorption for the excellent light harvesting properties of perovskite-based solar cells.

• 出版日期2014-9-4