Zero-dimensional hybrid tin halides with stable broadband light emissions

Considering the instability and toxicity of 3D Pb-based perovskite nanocrystals, lead-free low-dimensional organic-inorganic hybrid metal halides have attracted widespread attention as potential substitutes. Herein, two new tin-based 0D halides [H₄BAPP]SnBr₅·Br and [H₄BAPP]SnCl₅·Cl·H₂O (BAPP = 1,4-bis(3-aminopropyl)piperazine) were synthesized successfully based on [SnX₅]^3- as an emission center. Typically, [H₄BAPP]SnBr₅·Br and [H₄BAPP]SnCl₅·Cl·H₂O display broadband yellow and yellow-green light emissions originating from the radiative recombination of self-trapped excitons (STEs). The photoluminescence quantum yields (PLQYs) of the two compounds were calculated to be 19.27% and 2.36%, respectively. Furthermore, the excellent chemical and thermal stability and broadband light emissions reveal their potential application in solid-state white lighting diodes.