Lightweight Thin-film Solar Cell with Periodic Optical Nanostructure

AmberWave, Inc. has developed a method to laminate an ultra-thin (18 microns) monocrystalline Si layer to a conductive and fracture-resistant supporting layer such as a thin steel alloy foil. With this UTSi (Ultra-Thin Si) technology we have integrated front and rear cell processes based on the world-record PERL (Passivated Emitter Rear Locally diffused) silicon solar cell design, and have demonstrated efficiency of nearly 17% . Under the proposed SBIR Phase I project we will integrate a periodic array of metallic nanophotonic light trapping structures into the rear of our solar cell, to demonstrate enhanced light trapping in a 10 micron Si absorber layer. Phase I targets will be to demonstrate at least 12 watts/square foot, and 50 watts/pound, for unencapsulated UTSi solar cells with area of at least 2.5 square inches. In addition we will show a pathway to solar blankets capable of 16 watts/square foot and over 35 watts/pound, utilizing our UTSi solar cells with nanophotonic light trapping.