Scientists from University College London, working alongside partners in China and Switzerland, believe they’ve found a solution that could keep many of those gadgets running indefinitely without swapping out batteries. Their approach centers on newly engineered perovskite solar cells, designed specifically to harvest energy from everyday indoor lighting with record-breaking efficiency and long-term durability.

A New Take on Solar for Indoor Use

Unlike traditional silicon solar panels, which are best suited for bright outdoor sunlight, perovskite cells can be fine-tuned to absorb the softer, narrower range of wavelengths emitted by indoor light sources like LEDs and fluorescents. The challenge has been making them both efficient and stable. Imperfections in their crystal structure—tiny flaws known as traps—can snag electrons and waste energy as heat. Over time, these defects also cause the material to break down, reducing performance.The research team tackled this issue using what they call a “Triple Passivation Treatment” (TPT), a carefully chosen combination of three chemicals: rubidium chloride, N,N-dimethyloctylammonium iodide, and phenethylammonium chloride.

Together, these additives encourage the perovskite crystals to grow more evenly. The additives reduce internal strain, stabilize key ions, and prevent the crystals from clumping into separate phases that harm performance. In essence, they smoothed the path for electrons to move freely, boosting the cell’s ability to turn light into electricity.

Lead author Siming Huang likened the improvement to fixing a broken cake: “The solar cell with these tiny defects is like a cake cut into pieces. Through a combination of strategies, we have put this cake back together again, allowing the charge to pass through it more easily.