Wavelength Shifting Doped Core-Shell Nanocrystals for Solar Cells

Cost-effective concepts that can be added or retrofitted to existing solar cells are needed to enhance their energy conversion efficiencies. One suggestion involves optical down-conversion with photon multiplication (¿quantum cutting¿), which, in theory, can provide an increase in the single-junction photovoltaic conversion efficiency from 30.9% to 39.6%. This project will use the unique quantum confinement properties of nanocrystals to produce efficient down-converting emitter materials that can be overlayed as transparent thin films or composites onto the surface of solar cells. Phase I will (1) synthesize target doped core-shell nanocrystals designed to maximize ¿quantum cutting¿ for high energy solar photons; (2) thoroughly evaluate their optical properties, including their luminescence quantum yields; and (3) establish a model to predict the efficiency increases of solar cells incorporating the demonstrated ¿quantum cutting¿ materials. The best performing materials will be selected for optimization and scale-up in Phase II. Commercial Applications and other Benefits as described by the awardee: Successful down-converting overlays should add value to the full range of PV modules, increasing their efficiency and reducing their installed cost. The technology would be in high demand in the rapidly growing ~$1.5 billion terrestrial PV market, and would significantly increase PV market share over non-renewable energy sources.