LETTER pubs.acs.org/NanoLett Large Integrated Absorption Enhancement in Plasmonic Solar Cells by Combining Metallic Gratings and Antireflection Coatings

The incorporation of plasmonic scattering structures withphotovoltaics has been shown to increase solar cell photo-current and may lead to new opportunities for inexpensive, high efficiency solar cell designs.1-3 Experimentally, improved cur-rent generation has been found for scattering structures placed on top of,4-10 within,11 or on the bottom of12-14 photovoltaic devices. The earliest experiments with plasmonic particles on top of a photovoltaic device showed photocurrent enhancements of up to 20 over a narrow frequency range,5 and more recent experiments have shown integrated photocurrent enhancements of ∼7-12 % for quantum well structures,9 c-Si,8 and GaAs solar cells10 and ∼33 % for silicon-on-insulator devices.6 Experiments with grating structures have also shown significant enhancements.15-17 Similarly, results using a variety of full-field electromagnetic simulations and/or semianalytic methods have demonstrated that plasmonic particles can improve incouplin