Charging indoor devices with light from lamps and LEDs

Charging indoor devices with light from lamps and LEDs
by Clarence Oxford
Los Angeles CA (SPX) Jun 26, 2025

Perovskite solar cells (PeSCs) may soon power household electronics not from sunlight, but from fluorescent bulbs and ambient indoor lighting. Researchers from National Yang Ming Chiao Tung University in Taiwan have developed PeSCs tailored specifically for indoor conditions, as detailed in APL Energy, published by AIP Publishing.

Unlike rigid, heavy silicon-based solar panels commonly used outdoors, PeSCs are thin, lightweight, and flexible, opening possibilities for integration into wearable electronics and small Internet-of-Things (IoT) devices used indoors. These solar cells also offer the advantage of semi-transparency and tunable material properties.

"However, PeSCs can be made thin, lightweight, flexible, and even semi-transparent, whereas silicon panels are rigid and heavy, which limits their use to flat, durable surfaces," said study author Fang-Chung Chen.

To harness indoor light, the team adjusted the perovskite material's bandgap-the energy threshold needed for electrons to generate electricity-allowing greater absorption of light wavelengths typically emitted by lamps and LEDs. This level of spectral tuning is not feasible with conventional silicon cells.

However, optimizing the bandgap introduced defects into the perovskite layers. "Tuning the bandgap, unfortunately, accompanies a negative effect: It brings defects in the perovskite layers," Chen noted. To address this, the team implemented a passivation strategy using a chelating agent to reduce those defects and enhance stability.

Under strong light conditions approximating sunlight (around 12,000 lux), the PeSCs achieved a power conversion efficiency (PCE) of 12.7%, falling short of top-performing silicon panels. Yet, under much dimmer lighting at 2,000 lux-similar to office environments-the PeSCs reached a PCE of 38.7%.

"The indoor efficiency of PeSCs is higher, meaning that the photovoltaic products can be more suitable for versatile user scenarios, including cloudy outdoor, indoor, and other dim-light environments," Chen said.

To the researchers' surprise, the same defect-reducing treatment also improved the device's resilience to environmental degradation. "In the beginning, we only expected our approach could improve the device efficiency," Chen said. "Because the poor reliability of PeSCs is a large challenge for their adoption, we hope our proposed method can pave the way toward the commercialization of perovskite solar panels."

Research Report:Chelating agent-based defect passivation for enhanced indoor performance of wide-bandgap perovskite solar cells