Science

TU Delft PhD candidate achieves world record

Once upon a time, solar cells were cumbersome. They weren’t easy to build and their hefty weight meant they weren’t easy to install either. Fortunately, as everything from smartphones to laptops have become thinner and lighter over the past several decades, so have solar cells.

That said, they’re still a work in progress.

Thin-film silicon solar cells are among the lightest versions currently available. They may one day become widely used and replace many of their more expensive (and hefty) counterparts. Advocates say that their lightweight and flexible design makes them easy to use. Even better: they can be made from raw materials that are widely available and inexpensive.

Unfortunately, the cells currently contain absorbent material that allows a great deal of sunlight to pass through them. Entirely too much potential energy is lost due to this problem and these cells aren’t currently as efficient as those made out of crystalline silicon and other materials.

This is one of the reasons why Dr. Hairen Tan decided to focus his thesis at TU Delft on designing a new and improved version. In September, Tan earned a doctorate with honors for his thesis “Materials and Light Management for High-Efficiency Thin-Film Silicon Solar Cells” from the Department of Electrical Sustainable Energy.

“My PhD thesis was devoted to the development of advanced materials and novel light-trapping structures to increase the efficiency of thin-film silicon solar cells to make this technology more competitive in the market.” Tan said.

While conducting his research, Tan collaborated with members of the PV Laboratory of EPFL in Neuchâtel, Switzerland. With their assistance, he was able to achieve a world record: a thin-film silicon solar cell with an initial efficiency of 14.8%.

“I designed a novel modulated surface textured substrate for tandem solar cells in order to scatter and absorb light more efficiently in both sub-cells,” Tan said. “In this approach, micrometer-scale large surface features obtained by etching a glass substrate are combined with nano-scale features of a transparent electrode.”

Tan also collaborated with Professor Rene Janssen from Eindhoven University of Technology on a different solar cell with a record efficiency of 13.2%. From here, Tan’s design work will undergo further development.

“The next stage in the process is to test with a thin-film silicon solar cell producer whether the concept of modulated surface texture can be implemented in the production environment,” Professor Miros Zeman (EWI), who served as Tan’s promoter, said. “We are in contact with HyET Solar, a company that manufactures flexible lightweight solar foils.”

Editor Redactie

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