Options
2010
Conference Paper
Titel
SiNTO EWT silicon solar cells
Abstract
In this work we combine the SiNTO cell process with the EWT cell concept. All masking steps are performed by inkjet printing technology. The via-holes and laser-fired contacts are created by high-speed laser drilling. A new polishing process, which is suitable for inkjet masking, to pattern the interdigitated grid on the rear side is developed. For passivation purposes a thermal silicon oxide is used for the rear surface and a silicon nitride antireflection coating for the front surface. An e-gun evaporated aluminium/titanium/silver stack is used for the metallization, where the silver acts as a seed layer for a subsequent electro-plating step. Conversion efficiencies up to 16.9% on FZ material are obtained. The emitter is additionally analyzed on symmetric lifetime samples. Two different emitter diffusion processes, a 35 and a 65 ohm/sq. POCl3 diffusion process are regarded. An emitter diffused from a phosphorus doped silicon oxide layer in the same diffusion process as the 35 ohm/sq. emitter is analyzed as well. Emitter saturation current densities as low as 286 fA/cm2 are reached for an oxidized emitter.
Author(s)