Abstract: To improve the photoelectric conversion efficiency of a p-n junction solar cell by adding a minimum element thereto to widen the absorption wavelength range thereof. Solving Means Nano particles obtained by terminating surfaces of silicon nanoparticles having a diameter of not more than 5 nm with molecules of hydrocarbon are disposed on the outermost surface of a semiconductor forming a p-n junction solar cell that uses silicon or the like. These silicon nanoparticles absorb energy of ultraviolet light, and the energy is transferred to the p-n junction solar cell. In this way, a solar cell composite that efficiently utilizes light ranging to the ultraviolet region without requiring the use of additional wiring or the like is obtained.