Solar cells absorb sunlight and convert it into electricity. This process, however, is not perfect, and a large part of the solar energy is simply lost along the way. Some of it is lost as heat, while photons with insufficient energy pass through the cell without generating electricity. These are the sources of loss that most scientists in the field try to minimize, but there is another important one known as Boltzmann loss.
Solar cells gain efficiency by emitting light in fewer directions
