TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The anti-reflective coating comprises magnesium fluoride, silicone nitrate, titanium nitrate, silicon monoxide or silicon oxide nitrite. The absorber layer is copper-indium-gallium-diselenide and the junction partner layer is cadmium sulfide, tin oxide, zinc oxide, zirconium oxide or doped zinc oxide. The absorber layer comprises copper-indium-gallium-diselenide (CIGS) having a 110 crystallographic orientation, a 112 crystallographic orientation or no crystallographic orientation. The substrate: has a solid core; and comprises plastic, metal or glass.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The first refractive index is equal to the second refractive index. The first refractive index minimizes the reflection of light by the filler layer. The second refractive index is 1.4-1.9, preferably 1.5-1.9. The first and second refractive indexes are chosen so that light incident on the filler layer is refracted towards the center of the solar cell unit. The solar cell unit further comprises: an anti-reflective coating circumferentially disposed on the transparent tubular casing. In the solar cell unit, ri is ro less than or equal to e-outer ring, where ri is a radius of the cylindrical shaped solar cell, ro is the radius of the transparent tubular casing and eta -outer ring is the first refractive index and/or the second refractive index. The cell further comprises a water resistant layer circumferentially disposed on the transparent conductive layer, where the filler layer is circumferentially disposed on the water resistant layer. The transparent tubular casing is formed directly on the filler layer by casting or UV curing. The semiconductor junction comprises an absorber layer and a junction partner layer, where the junction partner layer is circumferentially disposed on the absorber layer and the absorber layer is circumferentially disposed on the back-electrode. The transparent tubular casing comprises many transparent tubular casing layers including a first transparent tubular casing layer and a second transparent tubular casing layer, where the first transparent tubular casing layer is circumferentially disposed on the filler layer and the second transparent tubular casing layer is circumferentially disposed on the first transparent tubular casing layer. The transparent conductive layer is coated with a fluorescent material.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The substrate comprises: a urethane polymer, an acrylic polymer, a fluoropolymer, polybenzimidazole, polyimide, polytetrafluoroethylene, polyetheretherketone, polyamide-imide, glass-based phenolic, polystyrene, crosslinked polystyrene, polyester, polycarbonate, polyethylene, polyethylene, acrylonitrilebutadiene-styrene, polytetrafluoro-ethylene, polymethacrylate, nylon 6-6, cellulose acetate butyrate, cellulose acetate, rigid vinyl, plasticized vinyl or polypropylene; and aluminosilicate glass, borosilicate glass, dichroic glass, germanium/semiconductor glass, glass ceramic, silicate/fused silica glass, soda lime glass, quartz glass, chalcogenide/sulfide glass, fluoride glass, a glass-based phenolic, flint glass or cereated glass.