The effects of down-conversion materials on solar cells

Cerium-doped yttrium aluminum garnet (YAG:Ce) is used as the down-conversion materials to improve light absorption of solar cells. Experimental results show that coating YAG:Ce phosphors on surfaces of single crystalline silicon solar cells can enhance internal quantum efficiency in short wavelength range. This indicates that more photons can be generated when shorter wavelength photons hit cell´s surface coated by the YAG:Ce phosphors. However, coating the YAG:Ce phosphors on the cell´s surface also causes more light reflection and loss of the photons of wavelength longer than 490nm, and leads to the reduction of external quantum efficiency and energy conversion efficiency.