Project Name: Controlling the Recombination Activity of Dislocations in III-V Solar Cells
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Urbana, IL
SETO Award Amount: $200,000
Awardee Cost Share: $50,000
Principal Investigator: Minjoo Lee

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

III-V solar cells, which are made of materials like gallium arsenide or gallium indium phosphide, can reach much higher efficiencies than silicon cells, but they are prohibitively expensive because of the way the III-V crystals are grown. This project team will work to lower the cost of III-V solar cells and increase their efficiency by mitigating defects in the cells’ crystalline structure.

APPROACH

To reduce costs, the team will grow III-V crystals on silicon wafers instead of on conventional III-V crystal seed wafers. The team will keep the silicon wafer and III-V crystal attached in the solar cell to eliminate defects that would typically be caused by separating them. Growing on silicon will introduce gaps in the III-V crystals that could lower efficiency, since charges cannot flow across these gaps. The team will test materials such as beryllium and carbon to determine what can best fill these gaps and boost efficiency.

INNOVATION

If the team successfully grows III-V crystal on silicon, the price of these crystal wafers will be significantly reduced. By testing additives, to determine the best chemical for mitigating efficiency loss from crystal defects, the team will make a valuable contribution toward higher-efficiency III-V solar cell technology. These achievements would contribute to future commercialization of lower-cost, higher-efficiency III-V solar cells.