On September 14, Ajeet Rohatgi, Regents’ Professor in the Georgia Tech School of Electrical and Computer Engineering, was named one of the 19 funding recipients in the Photovoltaics Research and Development Program as part of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy’s (EERE) SunShot Initiative.
Rohatgi’s project is entitled “Pushing the Efficiency Limit of Low-Cost, Industrially-Relevant Silicon Solar Cells by Advancing Cell Structures and Technology Innovations.” It will be funded for $1.125 million for the next three years. This project will advance manufacturable silicon cell technologies to above 22% efficiency through the use of passivated selective emitter and selective back surface field (BSF) contact geometries. The improved contact and metallization methods investigated during the course of the project will reduce recombination and improve cell performance by up to 2% absolute efficiency. Multiple fabrication methodologies will be investigated to determine the most cost-effective method for producing the laterally patterned doping profiles needed to realize this high performance cell technology.
Joining Rohatgi on this project as subcontractors are Fraunhofer Institute for Solar Energy Systems and the University of Konstanz, which are both located in Germany. Rohatgi is the founding director of the first university-based, Department of Energy Center of Excellence in Photovoltaics Research and Education, and he holds the John H. Weitnauer Chair in the College of Engineering and is a Georgia Research Alliance Eminent Scholar. Rohatgi has published over 500 technical papers and has been issued a total of 41 patents, including 19 U.S. patents. He is the founder and CTO of Suniva, Inc., a Georgia Tech spin-off company that is the first silicon solar cell manufacturing company in the southeast.
In addition, Suniva, Inc., a Georgia Tech spin-off founded by Rohatgi, was named as one of 21 projects funded by the Technology to Market Program. Suniva received a two-year $1.997 million contract from this SunShot Initiative, and Rohatgi is a subcontractor on the project. The company, which is the first silicon solar cell manufacturer in the southeast, will work on developing an advanced passivated emitter rear cell (PERC) structure that utilizes an aluminum grid on the back side instead of a conventional full-area aluminum structure. These bifacial cells will have lower stress and thus can be thinned down to save on silicon material costs. In addition, performance improvements are proposed that would lead to much finer silver gridlines to improve cell and module efficiency. These enhancements in the cell performance can feed directly into Suniva’s high-volume manufacturing line.
One of SunShot’s goals is to drive down the levelized cost of utility-scale solar electricity to $0.06 per kilowatt-hour without incentives by 2020. The projects and new funding aim to reach costs well below that threshold, furthering the Obama Administration’s commitment to advancing solar technology as a resource for clean energy in America’s low-carbon economy.
“Since 2008, the commitments made by the Department of Energy have contributed to solar PV’s deployment growing 30-fold and overall costs falling more than 60 percent,” said Under Secretary for Science and Energy Franklin Orr. “Continuing to invest in solar technologies will help to drive down costs even further for American consumers and ensure that the U.S. maintains global leadership in this century’s clean energy economy.”