Broad-range high-resolution optical spectroscopy of CH3NH3PbBr3 hybrid perovskite single crystals: Optical phonons, absorption edge, phase transitions
Full article
| Journal |
Optical Materials
ISSN: 1873-1252
, E-ISSN: 0925-3467
|
| Output data |
Year: 2023,
Volume: 20,
Pages: 100259
Pages count
: 1
DOI:
10.1016/j.omx.2023.100259
|
| Tags |
Hybrid perovskite CH3NH3PbBr3, Large single crystals, High-resolution optical spectroscopy, Phonons, Absorption edge, Structural phase transitions |
| Authors |
Anikeeva Vasilisa E.
1,2
,
Boldyrev Kirill N.
1
,
Semenova Olga I.
3
,
Sukhikh Taisiya S.
4
,
Popova Marina N.
1
|
| Affiliations |
| 1 |
Institute of Spectroscopy, Russian Academy of Sciences, Fyzicheskaya Street 5, Troitsk, Moscow, 108840, Russia
|
| 2 |
HSE University, Myasnitskaya Street 20, Moscow, 101000, Russia
|
| 3 |
A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Lavrentiev Avenue 13, Novosibirsk, 630090, Russia
|
| 4 |
Nikolaev Institute of Inorganic Chemistry Siberian Branch of the Russian Academy of Sciences, Lavrentiev Avenue 3, Novosibirsk, 630090, Russia
|
|
Funding (2)
|
1
|
Ministry of Science and Higher Education of the Russian Federation
|
121031700313-8
|
|
2
|
Russian Science Foundation
|
19-72-10132
|
Vibrational and structural properties have an enormous influence on optoelectronic properties of hybrid halide
perovskites CH3NH3PbX3 (X = I, Br, Cl), which are perspective materials for different photovoltaic applications.
Here, we report results of the first high-resolution optical spectroscopy measurements of large CH3NH3PbBr3
single crystals in wide frequency (20–20 000 cm 1) and temperature (5–300 K) ranges. Fit of polarized farinfrared
reflection spectra using Lorentz model of damped oscillators revealed parameters of three phonons at
room temperature and 38 phonons at 10 K. An analysis of mid-infrared transmission spectra gave evidence of a
strong anharmonicity in this hybrid perovskite. A splitting of some lines observed in the orthorhombic phase was
presumably assigned to the tunneling of the CH3NH3+ cation molecule between several potential energy minima.
The temperature behavior of the transmission spectra near the fundamental absorption edge was tentatively
explained by the competition between two different exciton transitions in CH3NH3PbBr3. Positions of spectral
lines and of the absorption edge measured at cooling and heating the sample demonstrate hysteresis loops in the
vicinities of phase transitions around 237, 155, and 149 K, thus revealing the first-order nature of all three phase
transitions in CH3NH3PbBr3.