TECHNOLOGY FOCUS - ELECTRONICS - Preferred Method: The step for providing the substrate provides an opaque substrate. The ohmic contact is formed at lower than 200 (preferably 100-175)degreesC. The ohmic contact between the electric conductive element and the opto-electronic layer is formed through a solid-state growth process. The step of providing the opto-electronic layer comprises to form semiconductor layers (240). The step of providing the substrate having opto-electronic layer comprises forming a first semiconductor layer on the substrate, forming an active layer (230) onto the first semiconductor layer, and forming a second semiconductor layer onto the active layer. The step for forming the electric conductive element comprises removing portions of the first semiconductor layer and the active layer to expose portions of the second semiconductor layer; and forming the electric conductive element on the first semiconductor layer and the exposed second semiconductor layer. Preferred Components: The electric conductive element comprises electrodes (270, 280). One of the semiconductor layers can be n-type doped semiconductor layer, and the other can be p-type semiconductor layer. The substrate can be a transparent substrate.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The electric conductive element can be made of materials such as nickel, palladium, germanium, silicon, selenium, gold, silver, platinum, gold-silver, silver-platinum, gold-platinum, or silver-gold platinum, or materials such as nickel, palladium, zinc, beryllium, magnesium, cadmium, gold, silver, platinum, gold-silver, silver-platinum, gold-platinum, or gold-silver platinum. The substrate can be made of silicon or glass.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Materials: The electric conductive element can be made of materials such as nickel, palladium, germanium, silicon, selenium, gold, silver, platinum, gold-silver, silver-platinum, gold-platinum, or silver-gold platinum, or materials such as nickel, palladium, zinc, beryllium, magnesium, cadmium, gold, silver, platinum, gold-silver, silver-platinum, gold-platinum, or gold-silver platinum. The substrate can be made of silicon or glass.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The substrate can be made of epoxy resin, poly methyl methacrylate, acrylonitrile butadiene styrene copolymer resin, and polymethyl methacrylate and sapphire, or polysulfones, polyethersulfones, polyetherimides, polyimides, polyamide-imide, polyphenylene sulfide and silicon-carbon thermosets.