Project Name: New Approaches to Low-Cost Scalable Doping for Interdigitated Back Contact Crystalline Silicon Solar Cells
Funding Opportunity: PVRD
SunShot Subprogram: Photovoltaics
Location: Golden, CO
SunShot Award Amount: $615,000
Awardee Cost Share: $68,333
Project Investigator: Sumit Agarwal

This project lowers the cost and reduces the complexity of manufacturing interdigitated back contact (IBC) mono-crystalline silicon solar cells, which provide a promising pathway to achieve $0.02-0.03 per kilowatt hour levelized cost of electricity (LCOE) by 2030. Currently, these types of cells require patterned doping of the back contacts, which adds several additional steps compared to the more traditional front-grid architecture. The research team will develop a photo-assisted, area-selective chemical vapor deposition that is highly scalable for large-area manufacturing, thereby reducing costs.

Approach

Ultra-high-efficiency mono-crystalline silicon solar cells provide the most promising pathway to achieve the $0.02-0.03 per kilowatt hour levelized cost of electricity (LCOE) target by 2030. Interdigitated back contact (IBC) cells are the most efficient crystalline silicon cells and can provide 25% efficiency by reducing recombination and shading losses. However, these type of cells only account for a small fraction of manufactured cells due to process complexity and high cost. One of the critical steps in manufacturing high-efficiency IBC cells is the patterned doping of the back contacts, which adds several additional steps compared to the more traditional front-grid architecture. This project will develop photo-assisted, area-selective chemical vapor deposition of p- and n-type hydrogenated amorphous silicon for direct dopant pattering without photolithography with 23% efficiency.

Innovation

This project will reduce the complexity and cost of manufacturing ultra-high-efficiency mono-crystalline silicon solar cells by developing a new simplified approach to produce patterned doping of the back contacts using photo-assisted, area-selective chemical vapor deposition instead of a complex series of steps involving photolithography. The new process for direct dopant patterning will be cost effective and highly scalable for large-area manufacturing. The adoption of this new step in manufacturing will enable significant module cost reduction and larger volume of cells on the market, leading to lower levelized cost of energy.