Computed and Experimental Absorption Spectra of the Perovskite CH_3NH_3PbI_3
Abstract
Electronic structure and light absorption properties of the perovskite CH_3NH_3PbI_3 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 hydrogen-like model. The computed absorption spectrum unravels a remarkable absorption "gap" 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 "gap" 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.
Additional Information
© 2014 American Chemical Society. Received: June 9, 2014; Accepted: August 22, 2014; Published: August 22, 2014. We are deeply indebted to Professor Teruya Ishihara for helpful comments on perovskite optical properties and for the agreement to use his absorption spectrum. H.B.S. gratefully acknowledges the access to the High Performance Computing Center at NTU. R.A.M. thanks the ONR and ARO for their support. M.E.M.B. is grateful to the Nanyang Technical University for supporting the Biophysics Center.Additional details
- Alternative title
- Computed and Experimental Absorption Spectra of the Perovskite CH3NH3PbI3
- Eprint ID
- 50245
- Resolver ID
- CaltechAUTHORS:20141007-153655799
- Office of Naval Research (ONR)
- Army Research Office (ARO)
- Nanyang Technical University
- Created
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2014-10-09Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field