New promise for solar energy

A breakthrough by WSU researcher Kelvin Lynn could help solar energy compete with fossil fuels for generating electricity.

Commercial success of solar technology has been constrained by the cells’ performance and cost. Key to addressing both concerns are the materials from which solar cells are made.

Seeking an alternative to silicon

Silicon solar cells represent 90 percent of the solar cell market. Because silicon is a costly material to use in manufacturing, it keeps the price of solar cells high. A low-cost alternative is cadmium telluride (CdTe), which outperforms silicon in real-world conditions, such as low light and hot, humid weather. CdTe also boasts a lower carbon footprint. The downside: Its performance is limited.

For decades, the maximum voltage available from a CdTe solar cell was fixed, making it less energy efficient than silicon-based cells. This practical limit was imposed by the quality of CdTe materials.

Breaking a longstanding barrier

Working with the U.S. Department of Energy’s National Renewable Energy Laboratory, Dr. Lynn’s team discovered a way to grow CdTe crystals that enabled precise control over purity and composition. His approach enabled fabrication of CdTe solar cells that made them nearly as efficient as silicon-based cells. The innovation establishes new research paths for developing solar cells that are more efficient and provide electricity at lower cost than fossil fuels.

Dr. Lynn’s research was funded through the Department of Energy’s SunShot Initiative, which aims to strengthen U.S. competitiveness in the solar industry and make solar energy cost-competitive with traditional energy sources.