Printed interdigitated front side metallisation for c-Si thin film solar cells
Three industrially applicable concepts
Thin crystalline silicon layers deposited on inexpensive substrates present a pr omising approach to achieve noticeably lower manufacturing costs compared to w afer technology. In contrast to conventional solar cells, both contact grids hav e to be applied on the front side, if the substrate is not conductive. In this work we introduce three concepts of realising such an interdigitated emitter an d base contact grid using screen printing and reactive ion etching. No photoli thography steps are involved and all processes are simple and appropriate for high-volume industrial solar cell production. The Buried Base Contact (BBC) conc ept turned out to be the most promising approach. However, due to high series resistance and shunting problems the conversion efficiency is still limited to 7 .6 %. A better definition of the base regions and improved properties of the b ase contacts using a more appropriate paste together with high resolution prin ting will lead to further improvements in cell performance.