Strong Electron-Phonon Coupling Induced Self-Trapped Excitons in Double Halide Perovskites

Chen, Baian1,2; Chen, Rui2; Huang, Bolong1,3

2023-03-01

10.1002/aesr.202300018

ADVANCED ENERGY AND SUSTAINABILITY RESEARCH   Impact Factor & Quartile

2699-9412

Double halide perovskites exhibit impressive potential for the self-trapped exciton (STEs) luminescence. However, the detailed mechanism of the physical nature during the formation process of STEs in double perovskites is still ambiguous. Herein, theoretical research on a series of double halide perovskites (Cs2BBCl6)-B-1-Cl-2 (B-1 = Na+, K+; B-2 = Al3+, Ga3+, In3+) regarding their electronic structures, exciton characteristics, electron-phonon coupling performances, and geometrical configuration is conducted. These materials have flat valence band edges and thus possess localized heavy holes. They also show high exciton binding energies, and their short exciton Bohr radius indicates that the spatial size of their excitons is comparable to the dimension of their single lattice. Based on the Frohlich coupling constant and Feynman polaron radius, the stronger electron-phonon coupling strength in Ga-series double halide perovskites is revealed. In particular, Cs2NaGaCl6 shows a high and effective Huang-Rhys factor of 36.21. The phonon characteristics and vibration modes of Cs2NaGaCl6 are further analyzed, and the Jahn-Teller distortion of the metal-halogen octahedron induced by hole-trapping after excitation is responsible for the existence of STEs. This study strengthens the physical understanding of STEs and provides effective guidance for the design of advanced solid-state phosphors.

double halide perovskites electron-phonon coupling excitons Jahn-Teller distortion self-trapped states

ESCI

English

Corresponding

National Natural Science Foundation of China/Research Grant Council of Hong Kong[N_PolyU502/21] ; Hong Kong Polytechnic University[1-ZE2V] ; Shenzhen Fundamental Research Scheme-General Program[JCYJ20220531090807017] ; Departmental of Applied Biology and Chemical Technology from the Hong Kong Polytechnic University[ZVUL]

Science & Technology - Other Topics ; Energy & Fuels ; Materials Science

Green & Sustainable Science & Technology ; Energy & Fuels ; Materials Science, Multidisciplinary

WOS:000956488700001

WILEY

Web of Science

1.Hong Kong Polytech Univ, Dept Appl Biol & Chem Technol, Kowloon, Hong Kong, Peoples R China
2.Southern Univ Sci & Technol, Dept Elect & Elect Engn, Shenzhen 518055, Peoples R China
3.Hong Kong Polytech Univ, Res Ctr Carbon Strateg Catalysis, Kowloon, Hong Kong 999077, Peoples R China

Chen, Baian,Chen, Rui,Huang, Bolong. Strong Electron-Phonon Coupling Induced Self-Trapped Excitons in Double Halide Perovskites[J]. ADVANCED ENERGY AND SUSTAINABILITY RESEARCH,2023.

Chen, Baian,Chen, Rui,&Huang, Bolong.(2023).Strong Electron-Phonon Coupling Induced Self-Trapped Excitons in Double Halide Perovskites.ADVANCED ENERGY AND SUSTAINABILITY RESEARCH.

Chen, Baian,et al."Strong Electron-Phonon Coupling Induced Self-Trapped Excitons in Double Halide Perovskites".ADVANCED ENERGY AND SUSTAINABILITY RESEARCH (2023).