TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The multicomponent nanoparticles comprise copper-selenium nanoparticles, indium-selenium nanoparticles, gallium-selenium nanoparticles, copper-sulfur nanoparticles, indium-sulfur nanoparticles, gallium-sulfur nanoparticles, copper-indium-selenium nanoparticles, copper-gallium-selenium nanoparticles, indium-gallium-selenium nanoparticles, indium-gallium-selenium nanoparticles, copper-indium-sulfur nanoparticles, copper-gallium-sulfur nanoparticles, indium-gallium-sulfur nanoparticles, copper-indium-gallium-selenium nanoparticles and copper-indium-gallium-sulfur nanoparticles. The precursor solution comprises copper-indium-gallium-selenium based single element, preferably indium acetate and gallium acetylacetonate. Preferred Method: The multicomponent nanoparticles are produced by low temperature colloidal method, solvothermal synthesis method, microwave method and ultrasonic synthesis method. The step (a) comprises ultrasonic treatment for dispersing and mixing slurry components. The non-vacuum coating is performed by spraying method, ultrasound spraying method, spin coating method, doctor blade method, screen printing method and inkjet printing method. The method further comprises drying after step (a) and (b). The step (b) is performed by sequentially repeating coating and drying. The step (c) is performed at 450-500 degrees C for 10-30 minutes.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The alcohol solvent comprises ethanol, methanol, pentanol, propanol and butanol. The chelating agent comprises monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, EDTA, nitrilotriacetic acid, hydroxy ethylenediamine triacetic acid, glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid, triethylenetetraaminehexaacetic acid, hydroxyethyl iminodiacetic acid and dihydroxyethylglycine, and the non-chelating agent comprises ethylene glycol, propylene glycol, ethyl cellulose and polyvinylpyrrolidone. EXAMPLE - No suitable example given.