Interdigitated front contact crystalline silicon solar cell

Interdigitated front-contact front-junction (IFC) silicon solar cell using advanced semiconductor technologies was studied. Narrow width, high aspect-ratio finger was made to reduce optical shadow effects and electrical resistive losses. Precise junction control and surface field passivation by ion implantation were employed. Self-aligned front local base contact was developed using spacer technology to prevent shunt leakage from emitter contact while maximizing emitter area. Total point-contact areal fraction was kept as low as 0.4% to reduce contact recombination and contact resistance was lowered by metal-silicide formation. To reduce optical normal reflection, angle shape metal grid was developed. By using parallel wires between solar cells, 20.1% maximum module efficiency was achieved.