Solar energy is a great idea because it’s nonpolluting and freely available. But solar panels are expensive and inefficient, so adoption of the technology around the world has been slow. The reason they are inefficient is that they don’t capture energy from all the wavelengths of light the sun emits. Now a group of scientists has discovered a way to inexpensively retrofit solar panels so that conversion efficiency can be vastly increased.
“Most of the light from the sun is emitted over a very broad window of wavelengths,” says Challa V. Kumar, Ph.D. “If you want to use solar energy to produce electric current, you want to harvest as much of that spectrum as possible.”