Tielyr Creason1,Mao-Hua Du2,Bayram Saparov1
University of Oklahoma1,Oak Ridge National Laboratory2
Tielyr Creason1,Mao-Hua Du2,Bayram Saparov1
University of Oklahoma1,Oak Ridge National Laboratory2
The environmental stability and toxicity challenges associated with luminescent lead halides have recently led a push in the advancement of ternary group 11 metal halides. As a representative family, A<sub>2</sub>MX<sub>3</sub> (A=Rb, K, NH<sub>4</sub>; M= Cu, Ag; X= Cl, Br, I) will be discussed in this presentation. A<sub>2</sub>MX<sub>3</sub> have been prepared through a variety of solid-state and solution synthesis techniques, yielding large single crystals and polycrystalline powders. The all-inorganic A<sub>2</sub>CuX<sub>3</sub> are found to consistently produce blue photoluminescence with record-high efficiencies of up to 100%. The high-efficiency emission in A<sub>2</sub>CuX<sub>3</sub> is attributed to self-trapped excitons (STEs) localized around Cu atoms within the 1D chains of [CuX<sub>3</sub>]<sup>2-</sup>. In contrast, A<sub>2</sub>AgX<sub>3</sub> are found to be broadband emitters. The broadband emission in these compounds is attributed to STEs and defect-bound excitons (DBEs). This dual-band emission mechanism is supported by comprehensive experimental data and density functional theory (DFT) calculations. Our results demonstrate the strong potential of A<sub>2</sub>MX<sub>3</sub> and related ternary group 11 halides for optical applications.