Contact, Screen Printing, Metallization, Metallisation, Perovskite Solar Cells
Summary / Abstract:
The main objective of the present paper is to summarize the work done in the Laboratory of Solar Cells (SiCelLab) form the Instituto Tecnológico y de Energías Renovables (ITER) in order to enable the possibility of using screen printing techniques as an alternative to the actual methods, applied by the scientific community for producing the metal contacts in perovskite based devices. Thus, the deposition of contacts made by screen printing with inks such as the ones based on graphite powders, epoxy resins and anhydrous solvents, due to their inherent low cost and processing temperatures, could lead to reducing the manufacturing costs and, therefore, help with the future commercialization of this kind of solar cell technologies. Bearing this in mind, optimal proportions of these three components have been combined, in order to obtain a basic ink recipe, suitable for printing purposes, which also provided the possibility to study the effect of using different solvents. The improvement of the derived ink recipes was achieved by producing samples, on the one hand, via screen printing so as to study their electric resistance and, on the other, via doctor blade so as to study their resistivity, in both cases by using a semiconductor characterization system, configured to operate as an ohmmeter. Also, a digital microscope was used to study in detail the homogeneity and adhesion characteristics of the deposited samples. Finally, it was concluded that the N, N- dimethyl formamide (DMF) and N-methyl-2-pyrrolidinone (NMP) are the solvents that allow to add greater amounts of graphite to the final mixture and, thus, to improve its conductivity, without impairing its printing capabilities.