Imagine a future where your TV remote, wireless keyboard, or smoke alarm never needs its batteries replaced.
Thanks to new research led by scientists at University College London (UCL), that future could soon be a reality.
An international team has developed a new type of solar cell that can harvest energy from ordinary indoor lighting with unprecedented efficiency and durability, potentially replacing disposable batteries in billions of low-power electronic devices.
The breakthrough comes from using a material called perovskite.
This crystal-like substance has become one of the most promising alternatives to silicon for solar panels in recent years. Unlike traditional silicon cells, which are designed for sunlight, perovskites can be fine-tuned to capture the specific wavelengths of light commonly found indoors.
This makes them especially attractive for powering the growing number of small electronics that make up the “Internet of Things.”
But there has always been a catch. Perovskite materials contain tiny flaws in their crystal structures, known as “traps.”
These traps act like potholes, stopping electrons from moving freely and turning their energy into waste heat instead of useful electricity. They also make the material degrade more quickly, limiting its lifespan.
To overcome this challenge, the UCL-led team developed a way to minimize these defects using a cocktail of chemicals. By adding rubidium chloride, they encouraged the perovskite crystals to grow more evenly, reducing strain in the material.
They also added two other stabilizing agents that kept different ions in the material—iodide and bromide—from separating and clumping, a process that previously caused the cells to lose efficiency over time.
The result was striking. In laboratory tests, the new solar cells converted 37.6% of indoor light at an intensity equivalent to a brightly lit office into electricity. This is a world record for perovskite cells optimized for indoor conditions and is about six times more efficient than the best commercially available indoor solar cells.
Equally important, the devices proved to be durable. In long-term testing, the improved cells kept 92% of their performance after more than 100 days, compared with just 76% for unmodified perovskite cells. In harsher stress tests—exposing them to 300 hours of intense light at 55°C—the new cells held on to 76% of their performance, while the standard versions dropped to less than half.
“These specially engineered cells show that it’s possible to harvest much more energy indoors than ever before,” said Dr. Mojtaba Abdi Jalebi, senior author of the study. “With billions of small devices relying on battery replacements, this technology could cut down on waste and provide a sustainable alternative.”
The research, published in Advanced Functional Materials, suggests that these indoor solar cells could last at least five years, making them a practical option for consumer devices.
Since perovskite materials are abundant, inexpensive, and can even be printed like newspaper ink, the team believes that scaling up production is realistic.
Lead author and PhD student Siming Huang compared the process to repairing a broken cake: “The solar cell with these defects was like a cake cut into pieces.
By carefully putting it back together with our chemical ingredients, we made it whole again—allowing the charges to flow smoothly.”
With industry partnerships already in discussion, the day may not be far off when everyday gadgets quietly power themselves using only the light already shining in our homes and offices.
