Researchers at National Yang-Ming Chiao Tung University in Taiwan have created a new kind of solar cell that works really well even under weak lighting. These new solar cells, called perovskite solar cells, are different from traditional ones. They can turn indoor light or even cloudy daylight into electricity better than silicon solar panels we usually see on rooftops.
The team tested these solar cells under a brightness level similar to what we find in offices, around 2,000 lux. In that test, the new solar cells reached a power conversion efficiency of 38.7 percent. This means they were able to convert a large part of the indoor light into usable electricity. That is much higher than what normal silicon-based solar panels can do indoors.
Professor Fang-Chung Chen, who led the project, said “We designed these cells to respond especially well to low-light environments like homes, offices, and even cloudy days outdoors”. “The indoor efficiency of perovskite solar cells is higher, meaning that the photovoltaic products can be more suitable for versatile user scenarios, including cloudy outdoor, indoor, and other dim-light environments.”
Traditional solar panels are usually made with silicon, which is heavy, rigid, and works best only in bright sunlight. But perovskite solar cells are thin, flexible, lightweight, and even semi-transparent.
These new features make them easier to place in many locations, including windows, furniture, or small electronic gadgets. The flexible nature of the material also means they can be used in curved or unusual shapes, which is not possible with hard silicon panels.
This success was made possible by something called “bandgap adjustment.” In simple terms, this is a way to fine-tune the material so it absorbs indoor light more effectively. To do this, the researchers changed the chemical makeup of the perovskite layer.
They mixed different molecules into the layer to improve how it captures light. This helped the solar cells take in energy from artificial lighting, like LEDs or fluorescent bulbs, and turn it into power.
Normally, perovskite materials have tiny flaws that make them unstable or less efficient. But the team in Taiwan used a special chemical method to “heal” these flaws. So their solar cells not only became more efficient but also more reliable and longer-lasting.
“We only expected our approach could improve the device efficiency,” said Chen. “Because the poor reliability of perovskite solar cells is a large challenge for their adoption, we hope our proposed method can pave the way toward the commercialization of perovskite solar panels.”
The team shared their findings in a research paper published this week in the scientific journal APL Energy. The paper is titled “Chelating agent-based defect passivation for enhanced indoor performance of wide-bandgap perovskite solar cells.”
The solar cells could be built into small devices that are used every day indoors, like remote controls, smartwatches, health trackers, and other smart home products. These are all devices that currently rely on batteries or plugs, but with this new technology, they could be powered just by the light inside your home.
The fact that these solar cells work well in dim lighting also means they can be used in places that don’t get much sunlight, such as urban apartments, offices, or even regions that often have cloudy weather. This could help people save electricity and reduce their environmental impact.
