Surface plasmon enhanced light absorption for thin film poly-silicon solar cell with hybrid structure and metal alloy nano-particles

Photovoltaic (PV) power is a promising choice as low-cost, environmentally friendly energy source. Thin-film solar cell is proposed as an alternative to reduce the cost due to its very thin silicon absorbers and utilization of cheap substrates. However because of the thin thickness of thin film solar cell, the light absorption is poor. In order to increase the absorption efficiency, surface plasmonic effect is used to improve the optical absorption. In this paper, we firstly attempt to use alloy to increase the light absorption. The results show Al-Cu alloy gives a better performance of absorbing light especially in the long wavelength region. We also build a nano-hole / embedded particle structure which can increase the absorption of the long wavelength light as well. In the end, we recommend using alloy material and the hole-particle surface plasmonic structure with a good back reflector in order to have a higher absorption of light to achieve a better performance thin film solar cell.