Design, fabrication and analysis of high efficiency inkjet printed passivated emitter rear contacted cells

Global warming, as well as the energy crisis as the world approaches peak oil production, are driving a need for more sustainable, cost effective, and efficient electricity sources. High efficiency photovoltaic designs, such as the PERL and PERC, use too many high temperature processes, expensive materials and complex manufacturing methods to be commercially viable. Work has been done to replicate the PERC cell structure using commercially viable methods, namely inkjet printing and metal plating. Inkjet printing has necessitated the use of plating as a self-aligning metallization method, and this plating has revealed some areas for concern: (1.) Ni plating on the rear point contacts; (2.) Poor adhesion between Ni and Si for the front finger contacts; and (3.) Non-uniform NiSi formation. Methods for mitigating these issues include different plating methods, improved surface preparation, and altered sintering conditions. Test structures and models validating these proposals are presented.