High Aspect Ratio Front Contacts by Single Step Dispensing of Metal Pastes

Abstract

A dispensing process was developed, allowing for a single step, contactless front side metallization of silicon solar cells. Compared to screen printing, the dispensed fingers showed superior geometry, with line widths down to 65μm across the whole wafer area and aspect ratios (height:width) of up to 0.5. Silicon solar cells were produced using both multi- and monocrystalline (cz) material. The efficiency gain on industrial solar cells was 0.6% absolute on multicrystalline material and 0.4% absolute on monocrystalline material, comparing the best dispensed cell with the best screen-printed cell. The average efficiency gain of the two groups was 0.3% (mc) and 0.2% (cz).