"By efficiently absorbing the light coming from lamps commonly found in homes and buildings, the materials we investigated can turn light into electricity with an efficiency already in the range of commercial technologies."Robert Hoye, Imperial College London

Smart devices like smartphones, smart speakers, and wearable health and wellness sensors are increasingly finding their way into our homes, offices and public buildings. However, the batteries they use can deplete quickly and also contain toxic and rare environmentally damaging chemicals, so researchers are looking for better ways to power the devices.

One way to power them is by converting indoor light from ordinary bulbs into energy, in a similar way to how solar panels harvest energy from sunlight, known as solar photovoltaics. However, due to the different properties of the light sources, the materials used for solar panels are not suitable for harvesting indoor light.

Now, researchers from Imperial College London and the University of Cambridge in the UK, and Soochow University in China, have discovered that new green materials currently being developed for next-generation solar panels could be useful for indoor light harvesting. They report their findings in a paper in Advanced Energy Materials.

"By efficiently absorbing the light coming from lamps commonly found in homes and buildings, the materials we investigated can turn light into electricity with an efficiency already in the range of commercial technologies," said co-author Robert Hoye in the Department of Materials at Imperial. "We have also already identified several possible improvements, which would allow these materials to surpass the performance of current indoor photovoltaic technologies in the near future."

The team investigated 'perovskite-inspired materials'. These were created to circumvent problems with materials called perovskites, which are being developed for next-generation solar cells. Although perovskites are cheaper to make than traditional silicon-based solar panels and deliver similar efficiency, perovskites contain toxic lead substances. This drove the development of perovskite-inspired materials, where the lead is replaced with safer elements like bismuth and antimony.

Despite being more environmentally friendly, these perovskite-inspired materials are not as efficient at absorbing sunlight. However, the team found that the materials are much more effective at absorbing indoor light, with efficiencies that are promising for commercial applications. Crucially, the researchers demonstrated that the power provided by these materials under indoor illumination is already sufficient to operate electronic circuits.

"Our discovery opens up a whole new direction in the search for green, easy-to-make materials to sustainably power our smart devices," said co-author Vincenzo Pecunia, a professor at Soochow University.

"In addition to their eco-friendly nature, these materials could potentially be processed onto unconventional substrates such as plastics and fabric, which are incompatible with conventional technologies. Therefore, lead-free perovskite-inspired materials could soon enable battery-free devices for wearables, healthcare monitoring, smart homes and smart cities."

This story is adapted from material from Imperial College London, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.