Crystals (Nov 2022)
A New Zero-Dimensional (CsK<sub>2</sub>)BiCl<sub>6</sub> Metal Halide: Boosting Emission via B-Site Mn-Doping
Abstract
The A site of zero-dimensional (0D) metal halides A3BiCl6 can be replaced by Cs and/or K, thus, four possible 0D A3BiCl6 forms exist, such as (Cs2K)BiCl6, (CsK2)BiCl6, K3BiCl6 and Cs3BiCl6. It is well known that Cs3BiCl6 has been reported. We predict that both (Cs2K)BiCl6 and K3BiCl6 do not have enough structural and thermodynamic stability, but (CsK2)BiCl6 should be a 0D stable A3BiCl6 candidate based on density functional theory (DFT). Furthermore, 0D (CsK2)BiCl6 metal halide was experimentally prepared by the solvothermal method. Though (CsK2)BiCl6 metal halide exhibits an indirect bandgap and poor luminescence properties, the emission can be boosted by B-site Mn-doping due to the efficient energy transfer from self-trapped excitons (STE) to the d-state of Mn ions. Our results enrich the family of 0D bi-based metal halides and provide guidance for the regulation of the structural and optical properties of metal halides.
Keywords