Discovery of Halide Perovskites and superlattices as a Design Problem

This presentation will offer the author’s perspective on a few central themes in the emerging field of Design and Discovery (D&D) of functional materials, using halide perovskites as an example. Materials have traditionally been introduced into inorganic photovoltaics (PV) either by incremental improvements on long-known substances (Si, CuInSe2, CdTe, In2O3) or via chemical substitution of known materials . This time-honored tradition leaves out the possibility of yet undiscovered but potentially useful materials. Inspection of databases of all inorganic materials previously made reveals that a few thousands are simply missing. These are combinations of chemical elements that are analogous to those appearing listed compounds but represent unreported compounds. One wonders if they are missing for a good reason (such as some inherent instability), or the community has simply not gotten around to try and make them, yet they might be interesting. Systematic laboratory synthesis of all such candidate-missing materials would seem a horrendous project. A possible alternative is to perform initial screening of hundreds of Missing Compounds by using first-principles thermodynamics and property calculation, and then attempt laboratory realization of narrower lists of missing materials. I will describe in this talk the idea behind such functionality-directed use of Quantum Thermodynamics and property screening applied to (i) traditional inorganic PV materials (ii) single halide perovskites and (iii) double halide perovskites and (iv) Design of artificial supe