NOVELTY - The method comprises depositing a layer of rod shaped or spherical nanoparticles on a substrate by contacting the substrate with a nanoparticle dispersion, treating the deposited layer of nanoparticles to prevent removal of the nanoparticles, depositing a further layer of nanoparticles onto the preceding nanoparticle layer on the substrate, repeating the treating step and depositing step, optionally thermally annealing the multilayer film, and producing a second inorganic film on a first inorganic film. The nanoparticles are active material forming nanoparticles.    USE - The method is useful for producing an inorganic film on a substrate, where the inorganic film is a dielectric coating or a transparent conducting layer and useful in an electronic device such as solar cells, light emitting diodes, transistors, photodetectors, light-emitting transistors, thermistors, capacitors and memristors (all claimed).    ADVANTAGE - The method is capable of effectively, simply and economically producing the inorganic film with high charge mobility and improved porosity, strength or optical properties.    DETAILED DESCRIPTION - The method comprises depositing a layer of rod shaped or spherical nanoparticles on a substrate by contacting the substrate with a nanoparticle dispersion, treating the deposited layer of nanoparticles to prevent removal of the nanoparticles, depositing a further layer of nanoparticles onto the preceding nanoparticle layer on the substrate, repeating the treating step and depositing step, optionally thermally annealing the multilayer film, and producing a second inorganic film on a first inorganic film. The nanoparticles are active material forming nanoparticles. The active material forming nanoparticles are nanoparticles for forming a semiconductor material. The nanoparticles are cadmium telluride nanoparticles, have a diameter of 1 nm, and are deposited in a thickness of 25 nm and dispersed in a solvent. The nanoparticle dispersion comprises different inorganic materials that upon thermal annealing form an active layer of a single composition. The thickness of the inorganic film is 200 nm. The deposition is solution processed by spin coating, dip-coating, printing, ink-jet printing, gravure printing, spray-coating, doctor blading or slot-die coating. The step of treating comprises a chemical treatment. The chemical treatment comprises contacting the layer of nanoparticles with a surface modifier. The step of thermal annealing comprises thermal annealing with a radioactive heat source, a laser or a pulsed flash of light. The substrate on which the layer of nanoparticles is deposited comprises a pre-deposited sol-gel layer or sol-gel produced inorganic film. The second inorganic film is: produced by depositing a layer of nanoparticles on the first inorganic film by contacting the first inorganic film with a nanoparticle dispersion, treating the deposited layer of nanoparticles to prevent removal of the nanoparticles, depositing a further layer of nanoparticles onto the preceding nanoparticle layer on the first inorganic film, repeating the treating step and the depositing step, and optionally thermally annealing the multilayer film; and produced by contacting the first inorganic film with a sol-gel and by sputtering. INDEPENDENT CLAIMS are included for:    (1) an electronic device;    (2) a solar cell; and    (3) a method for the production of a solar cell.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a method for producing an inorganic film on a substrate.