Taking advantage of the simple processing and rich chemistry of multinary halides including hybrid organic-inorganic halides, we controllable prepared a series of 2D, 1D and 0D crystal structures featuring perovskite-derived and non-perovskite crystal structures. Tunable light emission properties of the obtained materials were characterized using UV-vis absorption, photoluminescence (emission, excitation, time-resolved, temperature-dependent, quantum yield etc.) and density functional theory calculations.<br/><br/>In luminescent hybrid Sn- and Pb-based halides, the inorganic Sn/Pb-halide networks (or clusters) are usually responsible for the observed luminescence due to their relatively small energy gaps of the inorganic substructures compared to those of organic molecules. The low energy gaps of the inorganic substructures in such cases are ensured by the relatively small electronegativity difference between Sn/Pb and halogen elements, which results in valence bands dominated by halogen orbitals and conduction bands primarily made of metal orbitals. In principle, the band alignment in hybrid halides can be altered by (1) combining pairs of metal and halogen elements with large electronegativity difference to accommodate organic molecules’ frontier orbitals, or (2) by utilizing low-gap aromatic molecular cations. The hybrid metal halides studied in our group feature electropositive metals such as Zn and Cd, among others, and aromatic organic cations, yielding unusual band alignments at the organic-inorganic interface. Thus, we were able to obtain compounds showing type-I band alignment with bands near the band gap originating from the inorganic component, type-I band alignment based on organic molecules, and also type-II band alignment featuring both organic and inorganic states. Therefore, depending on the specifics of their band structures, highly tunable light emission of our compounds are attributed to inorganic or organic substructures, or a combination of both.<br/><br/>In this talk, I will provide fresh examples of highly luminescent multinary halides prepared in our group including several examples of broadband white-light emitters, and efficient deep blue emitters, both of which are sought for solid-state lighting applications.

High luminescent multinary halides: Crystal chemistry, properties and applications

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.