High-efficient ultra-thin solar cells

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 265-268
Next generations of solar cells require optical management at the sub-wavelength scale. In this regime, conventional light trapping techniques based on anti-reflection coatings and scattering structures are no more efficient. In this paper, we propose a multi-resonant ultra-thin solar cell with 25 nm-thick GaAs absorber. Strong optical confinement is achieved by metallic nanostructures. High absorption efficiency and low metal absorption losses are demonstrated numerically in the 500-800 nm wavelength range. The predicted efficiency of the ultra-thin solar cell is 17 %, with a nearly 100-fold decrease in absorber thickness compared to most thin-film photovoltaic devices.