OXFORD, England (FN) — In a laboratory on the outskirts of Oxford, researchers at Oxford PV are testing solar photovoltaic cells that could usher in a new era of renewable energy. The startup, a spin-off from Oxford University, is among several global firms developing tandem perovskite solar cells—technology that combines traditional silicon with synthetic perovskite materials to significantly boost energy conversion efficiency.
Perovskite, originally discovered in the Ural Mountains in 1839, now refers to a class of synthetically produced materials with similar crystal structures. These compounds, made from elements such as bromine, chlorine, lead and tin, are readily available and offer unique properties that allow solar panels to absorb a broader spectrum of sunlight.
Tandem perovskite cells can theoretically reach efficiencies of more than 47%, compared to the 33% ceiling of silicon-only panels. Oxford PV claims its modules could reduce electricity costs by about 10% over conventional silicon panels.
Despite promising lab results, concerns remain. Perovskite cells are more vulnerable to heat and moisture, and typically degrade faster than silicon. Additionally, the presence of lead—a toxic element—has raised environmental and health questions. However, researchers argue the amount of lead used is minimal compared to emissions from fossil fuels, and recycling protocols could mitigate disposal risks.
Oxford PV’s lab features environmental chambers that simulate years of wear in weeks, exposing cells to extreme heat, humidity and temperature fluctuations. “These tests give an idea of how the cells could degrade in the field,” said Laura Miranda, head of sustainability at Oxford PV.
Joseph Berry, a researcher at the U.S. National Renewable Energy Laboratory, said long-term reliability data is scarce. “Knowing that the module we’re making today will last 30 years is a hard material science question,” he said.
Still, industry leaders believe the benefits outweigh the risks. “The real value is how much energy you produce over the term of a power purchase contract,” said Scott Graybeal, CEO of California-based Caelux.
Oxford PV set a record in 2024 for the world’s most efficient residential solar module, reaching 26.9% efficiency. The company is manufacturing panels in Germany and recently deployed a 100-kilowatt pilot array to a U.S. solar farm.
Other firms are scaling up. Swift Solar, a U.S. startup, partnered with American Tower Corp. to install tandem panels on telecom towers. CubicPV and NREL have reported 24% efficiency, while Caelux shipped its first commercial batch of Active Glass panels.
China’s solar industry is also advancing rapidly. In April 2025, Trinasolar announced a record 31.1% efficiency for tandem cells. Oxford PV signed a licensing deal with the company for the Chinese market. Longi, another Chinese manufacturer, claims a 33.9% efficiency for a single cell.
As solar power grows—accounting for nearly 7% of global electricity generation and rising 29% in 2024—perovskite technology could play a pivotal role in accelerating the transition to clean energy.
