Patent ID: 8021909

Claim:
A method for making a silicon-quantum-dot planar concentrating solar cell assembly comprising the steps of: providing a substrate with a refractive index larger than that of air so that total reflection occurs at the interface between the substrate and air; providing a silicon-quantum-dot film on the substrate, wherein the silicon-quantum-dot film contains silicon quantum dots, wherein the thickness of the silicon-quantum-dot film is 0.1 to 100 micrometers, and the size of the silicon quantum dots is 1 to 10 nanometers; providing a silicon-oxide film on the silicon-quantum-dot film so that the substrate, the silicon-quantum-dot film and the silicon-oxide film together form a planar optical waveguide, wherein the thickness of the silicon-oxide film is 0.1 to 10 micrometers; and providing a solar cell near the planar optical waveguide, wherein sunlight is cast onto the silicon quantum dots so that they refract and diffract some of the sunlight and absorb some other sunlight and hence cast re-emitted light, wherein the refracted and diffracted sunlight and the re-emitted light reflect from the interface because of total reflection and become totally reflected light that is focused and directed to the solar cell.