Plasmon enhancement of optical absorption in ultra-thin film solar cells by rear located aluminum nanodisk arrays

摘要

In this work, in order to enhance the light absorption in one micron thick crystalline silicon solar cells, a back reflecting and rear located plasmonic nanodisk scheme is proposed. We investigate the scattering properties of aluminum nanostructures located at the back side and optimize them for enhancing absorption in the silicon layer by using finite difference time domain simulations. The results indicate that the period and diameters of nanodisks, thickness of spacer layer have a strong impact on short circuit current enhancements. The optimized Al nanoparticle arrays embedded in rear located SiCO_2 layer enhance J_(sc) with an increase of 47% from the non-plasmonic case of 18.9 to 27.8 mA/cm~2 when comparing with a typical stack with a planar aluminum back reflector and a back reflector with plasmonic nanoparticles. This finding could lead to improved light trapping within a thin silicon solar cell device.