Nanjing University Develops Transparent Window Coating Generating Solar Power

Scientists at Nanjing University in China have developed a transparent coating called a colorless and unidirectional diffractive-type solar concentrator (CUSC) that can transform ordinary windows into solar panels without obstructing the view. This coating uses layers of cholesteric liquid crystals to selectively diffract circularly polarized light towards the edges of the glass, where photovoltaic cells convert it into electricity, allowing over 64% of visible light to pass through and maintaining over 90% color accuracy. Prototype tests have shown an energy conversion efficiency of about 18.1% for the diverted light and have successfully powered small devices like a fan. The technology offers a scalable and practical approach to integrate solar energy production into buildings without altering aesthetics, potentially generating significant green energy and reducing carbon emissions on a large scale. While still in the prototype stage with current overall efficiency around 3.7%, further improvements in manufacturing and stability are underway to enable commercial use. This innovation marks a major advancement toward sustainable, self-sufficient urban environments by turning windows into silent, invisible power generators.