Hybrid Halide Perovskites: Advancing Optoelectronic Materials

The proposed research is broadly divided into three themes that are strongly intersecting. These are: Theme 1: Developing new perovskites towards tunable band gaps with high mobility and controllable doping (both p and n); Theme 2: Fundamental Behavior of Existing Hybrid Halide Perovskites and Newly Synthesized Systems; Theme 3: Fundamental properties of solution processed thin polycrystalline films, including heterostructures, and develop comparisons with single-crystals. KANATZIDIS at Northwestern will contribute to Themes 1 and 2 above. He has expertise in the preparation and characterization of inorganic materials, including in polycrystalline form and single crystals, and has been working on the title compounds for some years, focusing on their preparation in bulk and single-crystal forms, and their structural and property characterization. At Northwestern, he will be aided in his efforts by two graduate student researchers. The goals of the work at Northwestern will include determining the fundamental properties of the materials as a function of chemical composition, and to develop a scientific understanding of the correlation between these properties and the structure and composition of the material. This includes the prospect of observing and understanding mesoscale phenomena in phase-separated (biphasic) materials. The work in this theme will be divided into two parts, distributed over the two student researchers: (i) detailed studies of AMX3 and related compounds and (ii) synthesis of new materials using complex organic counterions in the system A/M/X/X’. The first part will be aimed at understating the chemical and physical properties of the existing compounds, which have demonstrated remarkable properties in devices or shown novel phenomena. The second is aimed at discovering better and more attractive materials as next generation systems in this class. The Northwestern researchers will work in close collaboration with researchers at UC Santa Barbara, and will exchange samples, and suggest new measurements on the different systems investigated. They will also provide reports, when required, and will participate in meetings with all the PIs and co-PIs at UCSB on a periodic basis.