TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The ink further comprises an acid. The ink has a pH of at least 1. The ink is slot die coated onto the substrate. Preferred Method: The preparation method further comprises adding an acid to the mixture. The coating step is solution-based. The solution-based coating step is spin coating, slot die coating, inkjet printing, dispensing, spray coating, blade coating, doctor blading, knife coating, curtain coating, gravure printing, flexo printing, offset printing, screen printing or pad printing. The film is annealed at a temperature of 50-500 degrees C. Preferred Components: The acid comprises hydrogen chloride (preferred), hydrogen bromide, hydrogen iodide, sulfuric acid, nitric acid, chloric acid, chlorous acid, sulfurous acid, hydrocyanic acid, perchloric acid, phosphoric acid, hypophosphorous acid or boric acid. The ammonium molybdate is ammonium heptamolybdate (preferred), ammonium dimolybdate, ammonium orthomolybdate, ammonium pentamolybdate, an ammonium molybdate of formula ( beta -(NH4)2Mo4O13), ((NH4)4Mo8O26), ((NH4)4Mo8O26), ((NH4)2Mo14O43) or ((NH4)2Mo22O67), and/or their hydrates. The inorganic salt is a metal halide. The metal halide is zinc chloride or calcium chloride (both preferred), zinc bromide, zinc iodide, calcium bromide, calcium iodide, beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, strontium chloride, strontium bromide, strontium iodide, barium chloride, barium bromide, barium iodide, radium chloride, radium bromide, radium iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, copernicium chloride, copernicium bromide or copernicium iodide. The conductive substrate comprises indium tin oxide. The cathode layer is aluminum metal. The cathode comprises indium tin oxide. The electron transporting layer comprises zinc oxide. The anode comprises silver metal.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The optoelectronic device is: formed of a normal configuration, comprising an anode, the hybrid molybdenum(VI) oxide film forming a hole transporting layer formed on the anode, an active layer formed on the hybrid molybdenum(VI) oxide film, and a conductive substrate forming a cathode formed on the active layer; and formed of an inverted configuration, comprising a cathode, an electron transporting layer formed on the cathode, an active layer formed on the electron transporting layer, the hybrid molybdenum(VI) oxide film forming a hole transporting layer formed on the active layer, and an anode formed on the hybrid molybdenum(VI) oxide film. The device comprises inorganic functional materials, small organic molecules or polymeric materials, and a combination of inorganic and organic functional materials. Preferred Components: The substrate is flexible or rigid. The thickness of the film is at least 1 nm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The solvent is a polar solvent comprising water (preferred), alcohols, furan, esters, acetonitrile, acetone, dimethylformamide, and/or dimethyl sulfoxide. The active layer comprises poly(3-hexylthiophene) and (6,6)-phenyl 61C-butyric acid methyl ester (P3HT:PCBM). EXAMPLE - No suitable example given.