Double perovskites using dual metal cations are promising candidates for Pb-free perovskites. This study shows that the electronic structures of double perovskites (A2B+B3+X6) can be significantly modulated by cation ordering changes. The bandgap of Cs2AgBiCl6 can be affected by changing octahedron alignments, and even zero gap states can be realized for the 2-dimensional BiCl6 (AgCl6) configuration. It is presented that different types of B+/B3+-site orderings in double perovskites could be the origin of bandgap dispersion. Comparative studies on the various compositions show that, among B+/B3+ cations, Tl/Bi could be promising for the suppression of ordering variation.
Bibliographical noteFunding Information:
This research was supported by the National R&D Program through the National Research Foundation of Korea (NRF) (Nos. NRF-2015R1A1A1A05001241, NRF-2015M1A2A2055836, and NRF-2017M3A7B4041698). Supercomputing resources including technical support were supported by the Supercomputing Center/Korea Institute of Science and Technology Information (No. KSC-2017-C2-0006).
© 2018 Author(s).
ASJC Scopus subject areas
- General Materials Science
- General Engineering