Heterovalent doping in lead halide perovskites was only marginally explored. Particular attention was focused on Bi3+ dopant, which was found to increase the a-phase stability for CsPbI3, leading to high efficiency of fully inorganic perovskite solar cells. It was recently demonstrated that the absorption onset red shift of the Bi-doped perovskite is due to the increased number of defect states and a significant increase in the sub-band-gap density of states. Here we computationally simulated the electronic properties of the Bi-doped MAPbI(3) (MA = CH3NH3+) perovskite to gain insight into the electronic structure modifications occurring upon heterovalent doping. Our results confirm the presence of deep trap states induced by the Bi dopant, with the Bi3+ acting as deep electron trap. The absorption onset red-shift observed upon Bi-doping of MAPbI(3) is mainly related to transitions to the Bi defect states, while the perovskite band gap is essentially unaltered.

First-Principles Modeling of Bismuth Doping in the MAPbI3 Perovskite

Mosconi, E.;De Angelis, F.
2018

Abstract

Heterovalent doping in lead halide perovskites was only marginally explored. Particular attention was focused on Bi3+ dopant, which was found to increase the a-phase stability for CsPbI3, leading to high efficiency of fully inorganic perovskite solar cells. It was recently demonstrated that the absorption onset red shift of the Bi-doped perovskite is due to the increased number of defect states and a significant increase in the sub-band-gap density of states. Here we computationally simulated the electronic properties of the Bi-doped MAPbI(3) (MA = CH3NH3+) perovskite to gain insight into the electronic structure modifications occurring upon heterovalent doping. Our results confirm the presence of deep trap states induced by the Bi dopant, with the Bi3+ acting as deep electron trap. The absorption onset red-shift observed upon Bi-doping of MAPbI(3) is mainly related to transitions to the Bi defect states, while the perovskite band gap is essentially unaltered.
2018
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/1442618
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