Scientists create solar cells that generate energy from indoor light at record efficiency

What just happened? Researchers at University College London have developed a new type of solar cell capable of efficiently generating power from indoor light, a breakthrough that could reduce reliance on disposable batteries. By refining perovskite-based photovoltaics to capture artificial light more effectively, the team has opened the door to powering everyday devices in homes and offices.

Perovskite, a material already gaining traction in outdoor solar panels, can be tuned to absorb the specific wavelengths of artificial light. Despite this promise, the compound has long faced obstacles. Tiny defects in its crystal structure known as traps impede electron movement, reducing efficiency and accelerating degradation.

To address these issues, the team introduced rubidium chloride during fabrication. The chemical promoted more uniform crystal growth, reducing strain and minimizing defects. They also added two stabilizing compounds to prevent halide ions like iodide and bromide from clustering into separate phases, a problem that previously disrupted electrical flow. This combined strategy enhanced both performance and durability.

The resulting solar cell achieved a conversion efficiency of 37.6 percent under indoor lighting conditions of 1000 lux, roughly equivalent to a brightly lit office. According to the researchers, this sets a record for a device specifically tuned for indoor use with a bandgap of 1.75 electron volts. In practical terms, the cells are six times more efficient than the best comparable indoor technologies currently available on the market.

Durability was another key focus. Tests over 100 days showed that the newly engineered cells retained 92 percent of their initial performance, compared with 76 percent for the control devices.