TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Oxide: The transparent conducting oxide is chosen from zinc oxide, indium oxide, tin oxide, cadmium oxide, lead oxide, nickel oxide, cobalt oxide, copper oxide, silver oxide, alumina, gadolinium oxide, and their mixed oxide, preferably zinc oxide or tin oxide. Preferred Material: The substrate comprises a semiconducting material, a metal film or foil. The semiconducting material is chosen from IV, III-V, II-VI, II-V, V-VI, and IV-VI semiconductor and their alloy, and organic semiconductor. The semiconducting material comprises silicon, complex of copper, gallium, indium, selenium and sulfur (Cu(Ga)InSe(S)), complex of copper, tin, zinc and selenium (Cu(Sn,Zn)Se), cadmium selenide (CdS), cadmium telluride (CdTe), or poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate). Preferred Metal: The metal is chosen from copper, gold, silver, palladium, platinum, rhodium, nickel, cobalt, iron, titanium, zinc, molybdenum, tungsten, aluminum and their alloy, preferably copper, gold, or nickel. Preferred Condition: The substrate is contacted with precursor solution and voltage is applied at 50-100 degrees C, preferably 60-90 degrees C for 5-30 minutes. The solution has pH of 2-12, preferably 5-8, more preferably 0-2. Preferred Precursor: The amount of precursor is 0.001-1 M. The precursor(s) is chosen from nitrate, chloride, sulfate, acetate, fluoride, iodide, bromide and hydroxide. The amount of oxidizing agent is 0.001-2 M. The oxidizing agent is chosen from nitrate, chlorate, oxygen and peroxide. The amount of halogen-containing compound is 0.0001-0.05 M. The halogen is fluorine. The halogen-containing compound is chosen from monofluoride, bifluoride, boron fluoride, silicon fluoride and transition metal fluoride.    TECHNOLOGY FOCUS - POLYMERS - Preferred Material: The organic semiconducting material is chosen from polypyrrole, polyaniline, polythiophene, polyacetylene, poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) and their derivative.