TECHNOLOGY FOCUS - ELECTRONICS - Preferred Unit: The solar cell unit further comprises a transparent tubular casing, a filler layer; a water resistant layer; and an antireflective coating circumferentially disposed onto the transparent conductive layer of all or a portion of the photovoltaic cells. The transparent tubular casing is circumferentially disposed on the filler layer and water resistant layer; and an antireflective coating circumferentially disposed on the transparent tubular casing. The length of the solar cell is 2 - 300 (preferably 2 - 30 or 30 - 300) centimeters. The cell unit comprises: a) a substrate, b) a first photovoltaic cell comprising a first back-electrode circumferentially disposed on a first portion of the substrate; a first semiconductor junction layer circumferentially disposed on the first back-electrode; and a first transparent conductive layer circumferentially disposed on the first semiconductor junction; and c) a second photovoltaic cell comprising a second back-electrode circumferentially disposed on a second portion of substrate; a second semiconductor junction layer circumferentially disposed on second back-electrode; and a second transparent conductive layer circumferentially disposed on second semiconductor junction. The first photovoltaic cell is adjacent to the second photovoltaic cell; the first transparent conductive layer is in serial electrical communication with the second back-electrode; the first transparent conductive layer is electrically isolated from the second transparent conductive layer; and the first back-electrode is electrically isolated from the second back-electrode. The photovoltaic cell comprises a first terminal photovoltaic cell at the first end of the substrate; a second terminal photovoltaic cell at the second end of the substrate; and at least one intermediate photovoltaic cell between the first terminal photovoltaic cell and the second photovoltaic cell, where the transparent conductive layer of each intermediate photovoltaic cell is in serial electrical communication with the back-electrode of an adjacent photovoltaic cell. The adjacent photovoltaic cell is the first terminal photovoltaic cell or the second terminal photovoltaic cell; or another intermediate photovoltaic cell. Several photovoltaic cells comprise at least three (preferably at least 10, especially at least 50, particularly at least 100) photovoltaic cells. A luminal or an exterior surface of the transparent tubular casing is coated with a fluorescent material. The semiconductor junction of a photovoltaic cell in the photovoltaic cells comprises a homojunction, heterojunction, heteroface junction, buried homojunction, p-i-n junction, or tandem junction. The semiconductor junction of a photovoltaic cell comprises an absorber layer (106) and a junction partner layer (108), where the junction partner layer is circumferentially deposed on the absorber layer. The photovoltaic cell further comprises an intrinsic layer circumferentially disposed on the semiconductor junction of the photovoltaic cell and the transparent conductive layer of the photovoltaic cell is disposed on the intrinsic layer. The intrinsic layer comprises an undoped transparent oxide or undoped zinc oxide. Preferred cell assembly: The solar cell assembly further comprises a transparent electrically insulating substrate that covers all or a portion of the first face of planar array; a transparent insulating covering disposed on the second face of planar array for encasing the several elongated solar cells between the transparent insulating covering and the transparent electrically insulating substrate; an albedo surface (where the albedo surface has an albedo that exceeds 80%) positioned to reflect sunlight into the solar cell units. The transparent insulating covering and the transparent insulating substrate are bonded together by a sealant. The elongated solar cells are configured to receive direct light from the direction of first face and from the direction of second face of the planar array. In solar assembly, the first solar cell unit and the second solar cell unit are electrically arranged in series or parallel. The transparent conductive layer is coated with a fluorescent material.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The back-electrode of a photovoltaic cell in the photovoltaic cells is made of aluminum, molybdenum, tungsten, vanadium, rhodium, niobium, chromium, tantalum, titanium, steel, nickel, platinum, silver, gold, and/or their alloy; or indium tin oxide, titanium nitride, tin oxide, fluorine doped tin oxide, doped zinc oxide, aluminum doped zinc oxide, gallium doped zinc oxide, boron dope zinc oxide indium-zinc oxide, metal-carbon black-filled oxide, graphite-carbon black-filled oxide, carbon black-carbon black-filled oxide, superconductive carbon black-filled oxide, epoxy, conductive glass, or a conductive plastic. The transparent conductive layer of a photovoltaic cell comprises carbon nanotubes, tin oxide, fluorine doped tin oxide, indium-tin oxide (ITO), doped zinc oxide, aluminum doped zinc oxide, gallium doped zinc oxide, or boron dope zinc oxide indium-zinc oxide. The absorber layer comprises copper-indium-gallium-diselenide and the junction partner layer comprises In2Se3 (indium selenide), In2S3 (indium sulfide), ZnS (zinc sulfide), ZnSe (zinc selenide), CdInS (cadmium indium sulfide), CdZnS (cadmium zinc sulfide), ZnIn2Se4 (zinc indium selenide), Zn1-xMgxO, CdS (cadmium sulfide), SnO2 (stannic oxide), ZnO (zinc oxide), ZrO2 (zirconium oxide), or doped ZnO. The water resistant layer comprises clear silicone, SiN (silicon nitride), SiOxNy, SiOx, or Al2O3 (aluminum oxide)(where x and y are integers), and a fluorescent material are coated on the water resistant layer. The fluorescent material is copper-activated zinc sulfide (ZnS:Cu), silver-activated zinc sulfide (ZnS:Ag), zinc sulfide, cadmium sulfide (ZnS:CdS), strontium aluminate activated by europium (SrAlO3:Eu), strontium titanium activated by praseodymium and aluminum (SrTiO3:Pr, Al), calcium sulfide with strontium sulfide with bismuth ((Ca,Sr)S:Bi), copper and magnesium activated zinc sulfide (ZnS:Cu,Mg), quantum dots of CdSe, a stilbene, trans-1,2-diphenylethylene, and/or (E)-1,2-diphenylethene, umbelliferone (7-hydroxycoumarin). The antireflective coating comprises MgF2 (magnesium fluoride), silicone nitrate, titanium nitrate, silicon monoxide, or silicone oxide nitrite.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The transparent tubular casing is made of plastic or glass, and it comprises 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, flint glass, or cereated glass; urethane polymer, acrylic polymer, fluoropolymer, silicone, silicone gel, epoxy, polyamide, or polyolefin; or polymethylmethacrylate (PMMA), poly-dimethyl siloxane (PDMS), ethyl vinyl acetate (EVA), perfluoroalkoxy fluorocarbon (PFA), nylon, cross-linked polyethylene (PEX), polypropylene (PP), polyethylene terephthalate glycol (PETG), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), or polyvinylidene fluoride (PVDF). The substrates comprises plastic, metal or glass; urethane polymer, acrylic polymer, fluoropolymer, polybenzamidazole, polymide, polytetrafluoroethylene, polyetheretherketone, polyamide-imide, glass-based phenolic, polystyrene, cross-linked polystyrene, polyester, polycarbonate, polyethylene, polyethylene, acrylonitrile-butadiene-styrene, polytetrafluoro-ethylene, polymethacrylate, nylon 6,6, cellulose acetate butyrate, cellulose acetate, rigid vinyl, plasticized vinyl, or polypropylene; or 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, glass-based phenolic, flint glass, or cereated glass. The substrate is configured so that a fluid (preferably air, water, nitrogen, or helium) is passed through the substrate. The filler layer is coated with a fluorescent material, and the layer or sealant comprises ethylene vinyl acetate (EVA), silicone, silicone gel, epoxy, polydimethyl siloxane (PDMS), RTV (room temperature vulcanizing) silicone rubber, polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), polycarbonate, acrylic, fluoropolymer, or a urethane.