In traditional liquid crystal displays (LCDs), less than 8 percent of the reflected light reaches the reader’s eye. The rest is absorbed by color filters and polarizers, says Jay Guo, a professor in the Department of Electrical Engineering and Computer Science at the University of Michigan and a co-author of the research. “The absorbed light is totally wasted,” Guo explains. It turns into heat; you can feel it if you put your hand near a monitor. “
To avoid this, Guo and his colleagues have developed afilter that can convert approximately 2 percent of light to energy that would otherwise be wasted. This could represent a significant amount to keep the electronic gadgets that we use every day running, scientists explain in the journal.ACS Nano..
The researchers created the new filter by adding semiconductor organic photovoltaic cells to a colored filter composed ofnano-thin metal sheets with spaced gridsvery precisely they act as resonants that trap and reflect light of a particular color. The color depends only on the space between the grooves. The new filter, just 200 nanometers thick, is one hundred times thinner than traditional color filters, a feature that could be attractive for use in future ultra-fine artifacts with display screens.