Patent ID: 8742252

Claim:
A solar cell unit comprising: (A) a solar cell, said solar cell comprising: a rigid substrate that is either (i) tubular or (ii) a solid rod; a back-electrode circumferentially disposed on the substrate; a semiconductor junction circumferentially disposed on said back electrode; and a transparent conductive layer circumferentially disposed on said semiconductor junction; (B) a filler layer circumferentially disposed on said transparent conductive layer, wherein said filler layer has a first refractive index and comprises a gel, an adhesive or a sealant; and (C) a transparent tubular casing circumferentially disposed on said filler layer thereby circumferentially sealing said solar cell, wherein said tubular casing has a second refractive index that is smaller or equal in value to said first refractive index, wherein r i ≥ r o η outer ⁢ ⁢ ring wherein r i is a radius of said cylindrical shaped solar cell; r o is the radius of said transparent tubular casing; and η outer ring is said first refractive index.