Scientists at Stanford are hard at work trying to improve the efficiency and durability of solar panels— two key factors that have kept the Sun from becoming a more popular source of energy. Their latest effort involves nanocrystalline-silicon, a material that has proven resilient and highly conductive, but not very good at absorbing light. Their solution, nanoshells — hollowed out spheres of silicon that trap and recirculate light much like a whispering gallery does sound. Balls of the crystalline material are dipped in silicon, then hydrofluoric acid is used to eat way the center of the sphere, leaving a path for light to enter. The shells trap the light, allowing more of it to be absorbed, and also reduces the effect of non-optimal angles on energy production. Hit up the source for a few more details.