Temperature-dependence of the band gap in the all-inorganic perovskite CsPbI3 from room to high temperatures.
Phys Chem Chem Phys
; 24(26): 16003-16010, 2022 Jul 06.
Article
em En
| MEDLINE
| ID: mdl-35730744
ABSTRACT
Understanding the micro-mechanism of the temperature dependence of the band gap in all-inorganic perovskites is of great significance for their optoelectronic and photovoltaic applications in various temperature environments. Herein, based on the recently developed electron-phonon renormalization method, the temperature-dependent band gaps of the optoelectronic perovskite CsPbI3 are studied from 300 K to 750 K (including orthorhombic, tetragonal, and cubic phases). It is found that the temperature-induced structural fluctuation makes the structure of perovskites deviate from the 0 K one, and the corresponding renormalized band gap differs from that at 0 K, especially for the high-temperature cubic phase (e.g., ΔEg is â¼177 meV at 600 K). However, within the temperature range of each CsPbI3 phase, the band gap Eg is enlarged slightly with the increase of temperature (e.g., ΔEg is â¼26 meV from 600 K to 750 K for the cubic phase), showing the insensitivity of the structural fluctuation effect to the temperature change. The reason is that the chemical characters of band edges are determined by PbI3-, and due to the strong correlation between Pb and I, the Pb-I bond lengths and Pb-I-Pb bond angles are almost unchanged as the temperature increases. Our work provides a fundamental understanding of the temperature-dependent band gaps in all-inorganic perovskites and shed light on the commercialization of perovskites.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Phys Chem Chem Phys
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China