The atomic-level structure of bandgap engineered double perovskite alloys Cs2AgIn1-xFexCl6

0539522 - ÚMCH 2022 RIV GB eng J - Journal Article
Ji, F. - Wang, F. - Kobera, Libor - Abbrent, Sabina - Brus, Jiří - Ning, W. - Gao, F.
The atomic-level structure of bandgap engineered double perovskite alloys Cs2AgIn1-xFexCl6.
Chemical Science. Roč. 12, č. 5 (2021), s. 1730-1735. ISSN 2041-6520. E-ISSN 2041-6539
R&D Projects: GA ČR(CZ) GA19-05259S
Institutional support: RVO:61389013
Keywords : lead-free halide double perovskites * Fe3+ doping/alloying * ssNMR
OECD category: Analytical chemistry
Impact factor: 9.969, year: 2021
Method of publishing: Open access
https://pubs.rsc.org/en/content/articlelanding/2021/SC/D0SC05264G#!divAbstract

Although lead-free halide double perovskites are considered as promising alternatives to lead halide perovskites for optoelectronic applications, state-of-the-art double perovskites are limited by their large bandgap. The doping/alloying strategy, key to bandgap engineering in traditional semiconductors, has also been employed to tune the bandgap of halide double perovskites. However, this strategy has yet to generate new double perovskites with suitable bandgaps for practical applications, partially due to the lack of fundamental understanding of how the doping/alloying affects the atomic-level structure. Here, we take the benchmark double perovskite Cs2AgInCl6 as an example to reveal the atomic-level structure of double perovskite alloys (DPAs) Cs2AgIn1−xFexCl6 (x = 0–1) by employing solid-state nuclear magnetic resonance (ssNMR). The presence of paramagnetic alloying ions (e.g. Fe3+ in this case) in double perovskites makes it possible to investigate the nuclear relaxation times, providing a straightforward approach to understand the distribution of paramagnetic alloying ions. Our results indicate that paramagnetic Fe3+ replaces diamagnetic In3+ in the Cs2AgInCl6 lattice with the formation of [FeCl6]3−·[AgCl6]5− domains, which show different sizes and distribution modes in different alloying ratios. This work provides new insights into the atomic-level structure of bandgap engineered DPAs, which is of critical significance in developing efficient optoelectronic/spintronic devices.
Permanent Link: http://hdl.handle.net/11104/0318615