30 Years of Partnership between NREL and First Solar on Cadmium Telluride Solar Cell Research

First Solar Inc., a partner of NREL recently celebrated 30 years on Cadmium Telluride Solar Cell Research. Earlier this partnership was named a Solar Cells Inc. They have been working together on thin film solar technology for more than two decades now. This collaboration is helping NREL fulfil its goal as a Department of Energy (DOE) national laboratory of commercializing technology through partnerships, and contributing to First Solar’s success in development, manufacturing, and operation of photovoltaic (PV) power plants with technology. NREL has more than 550 partners

In July, First Solar announced its intention to construct a $680 million solar panel manufacturing factory in Ohio, with an estimated 500 jobs. This announcement was just after seven months of the Biden administration, who share similar priorities which includes build a modern, sustainable infrastructure and an equitable clean energy future and ensure more jobs for America’s workers well supported by Secretary of Energy Jennifer Granholm.

In the early ‘90s, the collaboration was concentrated around the reliability, stability, and efficiency of the thin film cadmium telluride (CdTe) technology for its solar panels. Now majority of solar modules instead of cadmium telluride, are of crystalline silicon construction.

NREL was designated a national laboratory by President George Bush in 1991, and renamed from its original title, the Solar Energy Research Institute. In that time, unique approaches were taken in the research related to CdTe technology. This partnership have passed a series of thresholds together and hit multiple milestones during the journey.

The reliability of CdTe solar cells earlier was critical. Larry Kazmerski a retired NREL senior scientist said, “First Solar did not want to release anything until it was ready. They knew they had to have reliable modules. They tested everything to death and worked with NREL to validate efficiency and reliability.”

NREL Director of the Power Systems Engineering Center Ben Kroposki said, “When they were first coming out, they did not have very high-efficiency modules, but in working with them—and this was pretty early on—they always had a good idea of how to mass produce panels where they were basically making glass and depositing the CdTe on the glass,” he said. “They had a breakthrough working with some of the materials people at NREL that pushed efficiencies over 10%. That’s one of the big milestones: once they crossed over 10% efficiency and could start mass producing using their production techniques. That was a game-changer for these large-scale systems.”

Scalability has always set the First Solar partnership apart. First Solar was able to teach NREL a thing or two as well. Hence, they continue to work together closely.

“NREL recently designed and built a successful vapor transport deposition tool like the one used by First Solar to deposit CdTe films. This increases the relevancy of NREL’s work for First Solar. In addition to a long-standing Cooperative Research and Development Agreement (CRADA), we have recently partnered with them in two different cost-share projects that are studying the compatibility of NREL intellectual property with their process,” said David Albin, another lead CdTe researcher at NREL.

Gang Xiong, director of the First Solar California Technology Center, said, “The collaboration is fruitful as we can leverage the complimentary strength of both parties to advance the CdTe solar cell technology together.” He has witnessed the NREL–First Solar collaboration on CdTe research for a decade.

“This partnership truly does add up to more than the sum of its parts. First Solar is really good at screening innovative ideas rapidly and driving toward perfection in our R&D labs and our manufacturing lines. NREL is a great source of idea generation, and they have a lot of expertise in characterizing and understanding material/device performance-related issues. We openly share our R&D priorities with each other,” Gang Xiong added.

“We have a market of silicon that is always changing and improving and of course CdTe. If it wasn’t for CdTe, maybe we wouldn’t even be looking at perovskites now. People started to look for alternative thin films that are better. These guys are always keeping on top of things to see if they can’t themselves come into this and be a player or find out what the competition is doing. First Solar is here to stay with their CdTe, but they have shown that a thin film can be very, very competitive. The perovskite people are starting to mimic what First Solar did to show that these modules are really stable,” Kazmerski said.

“This partnership is one of the best examples of why the lab was set up originally and why it was developed as it was. It showed that the lab could really help a U.S. industry,” he added.