TECHNOLOGY FOCUS - ELECTRONICS - Preferred Methods: The method also comprises doping the organometal with dopant prior to adhering. The method preferably comprises two adhering steps and two heating steps. The first and second adhering steps use organometal containing p-type and n-type impurities, respectively. The first and second heating steps produce p-type and n-type oxide semiconductor thin films, respectively. The first adhering, second adhering, first heating, and second heating steps are carried out in order to fabricate a p-n junction. The metal oxide semiconductor thin film is produced using a sol-gel process.Preferred Components: The semiconductor thin film is n- or p-type. The organometal with n-type impurity is zinc acetate, zinc acetylacetonate, zinc formate, zinc hydroxide, zinc chloride, zinc nitrate, or their hydrates. The organometal with p-type impurity is copper acetate, copper formate, copper sulfate, copper chloride, copper nitrate, nickel acetate, nickel formate, nickel sulfate, nickel chloride, nickel nitrate, sodium cobalt nitrate, sodium cobalt acetate, sodium cobalt formate, sodium cobalt sulfate, sodium cobalt chloride, sodium nickel nitrate or their hydrates.The dopant for the organometal with n-type is aluminum nitrate, aluminum acetate, aluminum chloride, aluminum sulfate, aluminum formate, gallium nitrate, gallium acetate, gallium chloride, gallium sulfate, gallium formate, indium nitrate, indium acetate, indium chloride, indium sulfate, indium formate, boron nitrate, boron acetate, boron chloride, boron sulfate, boron formate, or their hydrates. The dopant for the organometal with p-type is aluminum nitrate, aluminum acetate, aluminum chloride, aluminum sulfate, aluminum formate, sodium nitrate, sodium acetate, sodium chloride, sodium sulfate, sodium formate, potassium nitrate, potassium acetate, potassium chloride, potassium sulfate, potassium formate, lithium nitrate, lithium acetate, lithium chloride, lithium sulfate, lithium formate or their hydrates. The substrate is made of metal, ceramic, glass, or heat-resistant plastic. EXAMPLE - Zinc acetate 2-hydrate, aluminum nitrate 9-hydrate, and ethanol were mixed by stirring at 80degreesC for 3 hours to obtain transparent mixed solution. A ceramic substrate was immersed in the mixed solution, immediately withdrawn, and dried at 260degreesC for 10 minutes to form organometal molecule film on the substrate. The temperature was maintained at 500degreesC for 1 hour to form aluminum-containing zinc oxide thin film constituting n-type semiconductor.