ASM Alternative Energy Contributes to High Aspect Ratio Conductor Printing on PERC Solar Cells – Solar Novus Today

August 8, 2016 Facebook Twitter LinkedIn Google+ Uncategorized

PERC cell front silver collector grid

Using an ASM AE Eclipse metallization platform, VectorGuard Fine-Line Stencils, and precision metal squeegees in combination with ISFH’s proven PERC solar cell production techniques, fired conductor fingers measuring 28 µm wide by 20 µm high were successfully printed.

“A fired aspect ratio higher than 0.7 is a remarkable achievement,” explains Tom Falcon, ASM AE Principal Engineer. “This project yielded conductor fingers with aspect ratios of 0.71; a result that enables greater solar cell electrical efficiency and lower overall production cost. Indeed, this is a very positive development for the PV industry.” ISFH, a German solar energy institute, is a developer of high efficiency Passivated Emitter and Rear Cell (PERC) solar cells.

This latest work, which leveraged metallization tools from ASM AE, resulted in optimized printing of the PERC cell front silver collector grid in order to improve the overall electrical efficiency of the cells. The ability to print narrower lines reduces shadowing, with taller lines providing lower electrical resistance. High aspect ratio lines with lines with excellent height uniformity produce the highest cell efficiency, while reducing the required quantity of silver paste required and, therefore, lowering costs.

“While this project was carried out in a lab environment, we target an industrially feasible process that is easily scaled up,” comments Dr. Thorsten Dullweber, ISFH Head of Photovoltaics, who was project team leader for this initiative. “All tools and materals used in the process are readilyavailable industry technologies; the expectation is that with uniform conductors this thin and high, an efficiency increase of 0.2% on average can be achieved in high volume production when compared to a standard screen printing process.” ASM AE and ISFH have collaborated on numerous PV industry projects, all with the aim of raising efficiency, improving productivity and reducing solar cell manufacturing costs.