Abstract:
The preparation of cementitious articles with a high surface finish, useful for the preparation of electrical devices, in particular photovoltaic devices, is described. The process involves exposing a prefabricated cementitious article to specific temperature and pressure intervals, for a given time period, and then coating the article thus treated with a polymer film, preferably based on polyimide, in specific quantities. Heat-resistant cementitious surfaces with a low, controlled and regular roughness, without point- like defects, suitable for the deposition of additional thin films, in particular metallic films and absorbent films, typically used for the manufacture of photovoltaic cells and/ or modules, are obtained.
Abstract:
The present invention relates to a substrate for a thin film photovoltaic module, characterized in that it is a cementitious product with average surface roughness Ra not higher than 500 nm. The invention also relates to the cementitious product as such, the thin film photovoltaic module comprising it, and a method of moulding both of them.
Abstract:
Aim of the present invention is to obtain cementitious products having smooth, planar surfaces and low thickness for applications having aesthetic purpose, of integrated architecture or as substrates, for example for a thin-film photovoltaic unit, with controlled curling and surface roughness, manufactured by mould casting of a fluid composition comprising: I. a hydraulic binder; II. one or more aggregates; III. an anti-shrinkage agent; IV. a superplasticizer agent; V. water, wherein the percentage by weight of said hydraulic binder in the composition is lower than that of said aggregates, and wherein said aggregates have a maximum diameter d max not greater than one third of the thickness of the product, the final product thus having an arithmetic mean surface roughness Ra not greater than 500 nm and curling not greater than 1500 micron.