Engineers say the revolutionary design, which could also keep people's homes warmer in winter months, would double the energy efficiency of an average household –  more than halving energy bills.

Senior author Professor Hin-Lap Yip from South China University of Technology said it is an organic version of photovoltaic (PV) solar panels.



These reduce energy bills, emit no pollution and require minimal maintenance, he says.

'Building-integrated photovoltaics are a great example of a market where silicon photovoltaics, despite their cheapness and performance, are not the most appropriate due to their dull appearance and heaviness', said Professor Yi.

'Instead, we can make organic photovoltaics into semi-transparent, lightweight, and colourful films that are perfect for turning windows into electricity generators and heat insulators.'

Researchers constructed a prototype capable of simultaneously outputting electricity and preventing excessive heating, according to the study published in the journal Joule.

This was achieved by performing a three-way balancing act between harvesting light for electricity generation, blocking it for heat insulation and transmitting it as a window normally would.



Researchers mixed and matched materials previously used for these different purposes. This led to the creation of a device that let the familiar visible portions of sunlight through, turned back the infrared light which is the major heating culprit and converted the near-infrared region in between into an electric current. It is estimated installing windows fitted with dual electricity-generating and heat-insulating properties could cut an average household's reliance on external electric sources by more than half.



This assumes every square inch of every window would be panelled with multi-functional solar cells.  These dual-function materials are still very much in their infancy, but researchers expect them to pave the way to new beneficial technologies. Professor Yip added: 'Making heat-insulating multi functional semi transparent polymer solar cells is just the beginning of exploring new applications of organic photovoltaics.

According to dailymail