Cylindrical Waveguides and Multi-Junction Solar Cell Investigated for Two-Dimensional Photorecepto-Conversion Scheme

Presented is a new cylindrical waveguide (WG) system based on a two-dimensional photoreceptor-conversion scheme (2DPRCS) for lamppost-type solar-cell systems. The optical properties of polydimethylsiloxane (PDMS) were evaluated as the WG material, and we found that the intrinsic optical loss of our PDMS-based waveguide (similar to 3 m(-1)) is low enough to be used in a 50 mm diameter lamppost 2DPRCS. The reflection solar concentrator (RSC) is also proposed, which can be combined with multijunction Si solar cells for lamppost-type systems that utilize sunlight coming not only from the south side but also from the east and west sides. We believe that, in the near future, this new approach based on 2DPRCS can enable high-efficiency concentrated photovoltaic systems.