A Novel Mechanism of Optical Spectrum Formation in the Cs₂NaInCl₆ Doped with Sb and Er
Autor
Ivashchenko, Inna A.
Makowska-Janusik, Małgorzata
Gulay, Lubomir D.
Kazarinov, Yurij G.
Lamonova, Karina V.
Smortsova, Yevheniia
Popov, Anatoli I.
Matras-Postołek, Katarzyna
Opublikowane w
Chemistry of Materials
Numeracja
Vol. 38, Iss. 11
Strony
5384-5396
Data wydania
2026
Wydawca
American Chemical Society (ACS)
Język
angielski
DOI
https://doi.org/10.1021/acs.chemmater.5c03256
Słowa kluczowe
band structure, crystals, electrical conductivity, ions, luminescence
Abstrakt
We present a mechanism describing the formation of the optical spectrum in double halide perovskites (DHPs), specifically Sb- and Er-doped Cs2NaInCl6. Optical measurements conducted at the Deutsches Elektronen-Synchrotron (DESY) facility between 10 and 300 K have revealed that the bandgap of Cs2NaInCl6 is significantly larger than previously estimated, measuring 6.7 eV. Based on density-functional theory (DFT) calculations, we conclude that the formation of In+ (5s2 optical center) is crucial to the luminescence observed in Cs2NaInCl6 microcrystals produced by precipitation techniques. The formation of In+ is associated with the transfer of electron density from Cl– to In3+, which occurs due to defects in Cs2NaInCl6, resulting in increased In content. This process is linked to the self-trapped exciton mechanism and the formation of defect-trapping levels within the Cs2NaInCl6 bandgap. Additionally, embedding Sb3+ (5s2 doped ion) and Er3+ affects both the crystal structure and absorption properties of Cs2NaInCl6 samples. These findings shed light on the intricate interactions between the synthesis, composition, and the optical behavior of both undoped and Sb3+, Er3+-doped Cs2NaInCl6 powder samples.
