Kabakova, Irina V. and Azuri, Ido and Chen, Zhuoying and Nayak, Pabitra K. and Snaith, Henry J. and Kronik, Leeor and Paterson, Carl and Bakulin, Artem A. and Egger, David A. (2018) The effect of ionic composition on acoustic phonon speeds in hybrid perovskites from Brillouin spectroscopy and density functional theory. JOURNAL OF MATERIALS CHEMISTRY C, 6 (15). pp. 3861-3868. ISSN 2050-7526, 2050-7534
Full text not available from this repository. (Request a copy)Abstract
Hybrid organic-inorganic perovskites (HOIPs) have recently emerged as highly promising solution-processable materials for photovoltaic (PV) and other optoelectronic devices. HOIPs represent a broad family of materials with properties highly tuneable by the ions that make up the perovskite structure as well as their multiple combinations. Interestingly, recent high-efficiency PV devices using HOIPs with substantially improved long-term stability have used combinations of different ionic compositions. The structural dynamics of these systems are unique for semiconducting materials and are currently argued to be central to HOIPs stability and charge-transport properties. Here, we studied the impact of ionic composition on phonon speeds of HOIPs from Brillouin spectroscopy experiments and density functional theory calculations for FAPbBr(3), MAPbBr(3), MAPbCl(3), and the mixed halide MAPbBr(1.25)Cl(1.75). Our results show that the acoustic phonon speeds can be strongly modified by ionic composition, which we explain by analysing the lead-halide sublattice in detail. The vibrational properties of HOIPs are therefore tuneable by using targeted ionic compositions in the perovskite structure. This tuning can be rationalized by non-trivial effects, for example, considering the influence of the shape and dipole moment of organic cations. This has an important implications for further improvements in the stability and charge-transport properties of these systems.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ORGANIC-INORGANIC PEROVSKITES; ORGANOMETAL TRIHALIDE PEROVSKITE; LEAD HALIDE PEROVSKITES; MECHANICAL-PROPERTIES; OPTICAL PHONONS; LOW-COST; PHASE; TEMPERATURE; EFFICIENCY; CH3NH3PBBR3; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Grifoni > Group David Egger |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 Mar 2020 07:23 |
| Last Modified: | 20 Mar 2020 07:23 |
| URI: | https://pred.uni-regensburg.de/id/eprint/14714 |
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