A team of researchers led by NYU Tandon has found a simple yet powerful way to make cadmium telluride (CdTe) solar panels more efficient and reliable.
Their innovation?
An ultra-thin protective coating that shields the panels during a critical step in the manufacturing process—leading to a 13% increase in power output.
CdTe solar cells work differently from the more common silicon panels seen on rooftops. Instead of using thick silicon layers, CdTe panels use a much thinner layer of cadmium and tellurium compounds spread over glass.
This makes them cheaper to produce and better at working in high heat and low light—making them especially useful in hot, sunny places like the Caribbean or near the equator.
These types of panels are most often used in large solar farms and currently make up about 40% of utility-scale solar installations in the U.S.
But they’ve had a long-standing problem: the heat used to add metal wiring during manufacturing can damage the solar cell’s internal structure. The damage happens at the boundaries where tiny crystals inside the material meet—like cracks in a tiled floor—causing the panels to lose efficiency.
To fix this, the researchers added a paper-thin layer of special oxide coatings—either aluminum gallium oxide (AlGaOx) or silicon oxide (SiOx)—before the metal wiring step.
These coatings automatically collect at the weak points between crystals, acting like invisible armor. At the same time, they stay out of the way of the parts of the surface that need to make electrical contact.
This small addition made a big difference. The coated panels produced more voltage—up to 850 millivolts, compared to 750 before—and improved another key performance measure called the fill factor, which reflects how well the solar cell converts sunlight into usable electricity.
The coating is added using a common method in electronics manufacturing called spin-coating, which is easy to use and affordable. Better yet, it works with different metals, including gold and molybdenum, and may pair well with other materials like nitrogen-doped zinc telluride, which help the panel carry electricity more efficiently.
Professor André Taylor, who co-led the study, says the discovery is a “straightforward” change that can fit into current production methods.
It could play a big role in making U.S.-made solar panels more competitive, especially as the country works to rebuild its solar industry after losing ground to overseas manufacturers.
The technology also brings a bonus: tellurium, one of the key materials used in CdTe panels, is often found in copper mining waste—meaning this innovation could also turn industrial leftovers into clean energy solutions.
