Solar cells are relatively inefficient at gathering the total range of sunlight’s spectrum that falls on them every day. Trying to find a way to capture more than a single wavelength or narrow band of the solar light, scientists at Massachusetts Institute of Technology (MIT) and at Peking University in China propose putting a strain on solar cells, creating a spatially varying bandgap that would react to more of the colors in light and thus give off more electricity. Changing the bandgap in a solar collector’s material enables excitation of electrons from not just visible light, but from energy sources such as infrared radiation. This has the potential to increase the cell’s energy output enormously since most of the sun’s radiation is in invisible form. Bandgap is a complex concept, and MIT provides a brief tutorial here. MIT’s news office reports: “’We’re trying to use elastic strains to produce unprecedented properties,’ says Ju Li, an MIT professor and corresponding …