Metallization of Rear Local Point-Contacts for Industrial PERC Solar Cells

Abstract

Metallization of rear point-contacts with a modified Al paste is reported for industrial PERC solar cells. The properties of point-contacts were investigated with a detailed study of Al paste, firing process, point-contact pitch as well as point-contact size. With the modified Al paste, it was demonstrated that void-free point-contacts could be obtained, and the point-contact depth could be controlled within a range of 13μm to 55μm, and Local Back Surface Field was 1.5-2.0μm thicker than that with a normal Al paste. Compared to cells with normal Al paste, the average efficiency of cells with modified Al paste was 0.16%abs higher.