Plasmon-enhanced deep-subwavelength lateral nanowire solar cells

Abstract

High performance deep-subwavelength lateral GaAs nanowire solar cells decorated with Au nanoblocks are proposed and studied through coupled three-dimensional optoelectronic simulations. The results show that Au nanoblocks signi cantly improve the absorption for TE polarized light mainly due to the excitation of localized surface plasmon. Surface local and near-eld enhancement are two unique properties of surface plasmon, which concentrate light and transfer energy to nanowires. In addition, the absorption cutoff wavelength is remarkably extended due to the effect of localized surface plasmon resonance which enhances the con nement of long-wavelength modes for deep-subwavelength nanowires. For the nanowire with diameter less than 150 nm, the photoelectric conversion e ciency is improved by 37%~43% after introducing Au nanoblocks, which can reach 12% for 90 nm-diameter nanowire. This work provides a feasible way for the advancement of high-performance deepsubwavelength nanoscale solar cells.