Solar panels only produce energy from a small section of the total wavelength spectrum of light. I believe some panels have a mirrored back to pass light through the solar panel a second time. Much of the light can never be converted because it is at the wrong wavelength.
Does anyone know if attempts have been made to coat the top of the reflective back surface with materials that would shift the wavelength of light to to the region which can be converted by the solar panel? So that the second pass through has more bang in it?
Since I haven't seen anything like that on the market then perhaps its not possible or too expensive for any gain.
Please do share your thoughts.