PROJECT PROFILE: Colorado State University (FY2018 Photovoltaics)

Project Name: Doping CdTe and CdSeTe for Higher Efficiency
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Fort Collins, CO
SETO Award Amount: $750,000
Awardee Cost Share: $187,500
Principal Investigator: Walajabad Sampath

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

Adding different elements into the absorber of a solar cell in low concentrations (known as dopants) is one strategy to make a solar cell. However, this is at the cost of dopant sites that remain non-activated, which further contribute to recombination effects and overall performance losses. This team will produce arsenic-doped CdTe cells and arsenic-and-antimony-doped CdSeTe cells with the goal of increasing cell efficiency by 3% to 22%. Arsenic and antimony are in Group V of the periodic table of the elements, and this project will provide a framework for testing cells doped with Group V elements.

APPROACH

The team will make CdTe and CdSeTe cells comprised of coatings containing arsenic and antimony additions. They will measure current-voltage and photoluminescence and perform cell simulations to determine voltage, charge carrier density, and cell uniformity. They team will use ion mass spectrometry to examine the effects of the dopants and to see how heat activates them. These results will guide research on performance efficiencies by lending insight into the variables influencing material behavior and the impacts on a cell’s electrical properties.

INNOVATION

Suppression of recombination through improved cell fabrication and enhanced performance via process optimization can minimize and control energy losses in thin-film PV cells. The use of these dopants in thin-film CdTe CdSeTe solar cells may lead to breakthroughs in efficiency and cost reduction.