Project Name: Bringing High-Efficiency Silicon Solar Cells with Heterojunction Contacts to Market with a New, Versatile Deposition Technique
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Tempe, AZ
SETO Award Amount: $1,000,000
Awardee Cost Share: $250,000
Principal Investigator: Zachary Holman

-- Award and cost share amounts are subject to change pending negotiations --

To lower the cost of silicon heterojunction (SHJ) solar cells, this project team will use an innovative technology called aerosol impact-driven assembly (AIDA) to deposit the cell layers during manufacturing.  SHJ cells have electrodes made of three layers of material that conduct charge. With 26% efficiency, they are the most efficient silicon solar cells, but their high capital expenditure requirements (CapEx) make them more expensive than less-efficient cells. AIDA can be used to apply a wide variety of materials in thin layers quickly, continuously, and without damage. This team estimates that AIDA will reduce the CapEx for SHJ cells by more than 60% while maintaining their durability and high efficiency.

APPROACH

The researchers will use AIDA to deposit layers of conductive, transparent metal oxide onto silicon and ensure that the ability of these layers to conduct electrons, along with other properties, are competitive with the state of the art. Then they will integrate the layers into very small SHJ cells to test their properties and the cell’s efficiency, durability, and performance. The team will then scale up the hardware and manufacturing process to fabricate standard-size SHJ solar cells with a high manufacturing throughput. They will again test these AIDA-deposited cells and show that they can stand up to heat, moisture, and changing temperatures.

INNOVATION

The project team has identified AIDA as an innovative way to quickly and safely deposit a wide variety of materials on silicon wafers, allowing testing of many materials in order to determine the ideal combination of electrode layers in SHJ cells. Unlike current techniques for depositing thin layers on silicon, AIDA can be used as a continuous rather than batch process, and does not have a significant risk of damaging the silicon. Because of these properties, AIDA will lead to much lower costs and thus larger-scale manufacturing of high-efficiency SHJ solar cells.