Understanding configuration of geopolymer materials for application in solar-cells

Geopolymers are ceramic-like inorganic polymers, that nowadays push through as alternatives to concrete materials, which is important for civil engineering as the geopolymers do not contribute to energy and environmental issues. Specifically, a much lower environmental footprint is present which significantly reduces CO2 emission, and opens up the space for energy conservation by applying a completely new approach. A particularly neat contribution in the overlapping areas of construction and energy materials could arise from preparing geopolymers in the form of a paste that can further be developed into thin-films (TF). Such conductive and transparent films open op the possibility for application in solar-cells. In this work, we focused on the chemical and (micro)structural changes that occur during the (pre)mullite-based geopolymer curing. Various factors influenced changes, such as type of ions in activation solution and additives that improve targeted properties of material. Having this in mind, we examined the conditions behind the (geo)polymerization to obtain optimized samples which were characterized by DTA-TGA, FTIR, XRD, SEM and IS. Particular attention was devoted to ssNMR study of the evolution course of the geopolymer system. Obtained results enabled a better understanding of the influence of chemical composition and homogeneity of constituents on the resulting (micro)structural and electrical characteristics of studied samples. We demonstrated a challenging development process including shift from relatively porous bulk to thin-film configuration, to broaden the applicability of geopolymers to vertical facade photovoltaic application.