TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The photo-luminescent medium is sulfur phosphate chloride doped with europium (SR5(PO3)3Cl:Eu) or barium magnesium aluminum oxide doped with europium (BaMgAl10O17:Eu) for converting UV light into a blue light; BaMgAl10O17:Eu or cerium terbium magnesium aluminum oxide doped with europium ((Ce,Tb)MgAl11O17:Eu) for converting UV light into a green light; magnesium cerium oxide doped with manganese (Mg4CeO5.5:Mn) for converting UV light into an orange light; yttrium oxide sulfide doped with europium (Y2O2S:Eu) for converting UV light into a red light; barium strontium silicon oxide doped with europium ((Ba,Sr)2SiO4:Eu) for converting blue light into green light; yttrium aluminum oxide doped with cerium (Y3Al5O12:Ce), (Ba,Sr)2SiO4:Eu or lithium- alpha -silicon aluminum oxynitride doped with europium (Li- alpha -SiAlON:Eu) for converting blue or green light into a yellow light; calcium- alpha -silicon aluminum oxynitride doped with europium (Ca- alpha -SiAlON:Eu) or strontium calcium aluminum silicon nitride doped with europium ((Sr, Ca)AlSiN3:Eu) for converting blue light or green light into an orange light; calcium sulfide doped with europium, strontium sulfide doped with europium or calcium aluminum silicon nitride doped with europium for converting blue light or green light into a red light; or inorganic compound comprising a host and activator. The host is a metal oxide, sulfide, nitride or oxynitride. The photoconductive layer is made of copper indium selenide (CIS) or copper indium gallium selenide (CIGS); and further grown with a cadmium sulfide (CdS) layer on it to obtain a photoconductive layer having a p-n type CIGS/CdS or CIGS/CdS composite structure. The transparent layer is a transparent substrate made of soda lime glass (SLG), low iron white glass or alkali-free glass. The front electrode layer is made of a transparent conductive oxide consisting of tin oxide, indium tin oxide, zinc oxide, aluminum zinc oxide, gallium zinc oxide or indium zinc oxide.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The activator is cerium, terbium, europium, manganese or praseodymium. The back electrode layer is made of molybdenum; or silver, aluminum, chromium, titanium, nickel or gold. The photoconductive layer is made of an amorphous silicon, polysilicon or microcrystalline silicon.