Light induced silver and copper plating on silver screen-printed contacts of silicon solar cells

Abstract

Abstract In this paper we present the results of solar cell’s screen printed contacts thickening by light induced plating (LIP) of Cu and Ag. Light-induced and light-assisted plating techniques are compared. Plating bath current versus illumination intensity, the potentials of metallic anode, front and back surfaces of the solar cell were measured and analyzed for all possible plating modes. The current-voltage behaviour of cells under illumination in a plating bath for the cases of electrically insulated and non-insulated back-surface of a cell is analyzed and discussed. Finally, the exact values of current/voltage/illumination intensity for optimal depositions and a general recipe for their determination for different plating materials are given. The quality of deposited layers, state of contact-line and anti-reflective coating surface were controlled after plating by cross-section and planar-view SEM observations. The electrical properties of plated contacts and their effect on overall efficiency of solar cell were investigated by measuring contact-line resistance and dark- and light I–V solar cell measurements. The absence of short-circuits was verified by imaging with an infra-red camera.