A glass unit includes an energy collecting layer attached to a light directing device for collecting a light energy from the light directing device, and an energy converting layer electrically coupled to the energy collecting layer for converting the light energy into an electric energy, and the light directing device includes a number of nanometer particles to direct the light energy toward the energy collecting layer. The light directing device includes one or more glass layers, and a light collecting panel attached to the glass layer with a bonding layer and made of polymer materials which are mixed with the nanometer particles to form the light collecting panel.