NOVELTY - The method comprises attaching a layer, other substrate layers and/or substrate by grafting of particles forming adhering points for the layer or substrate to be deposited or printed. The received layer is an absorbent layer (on the substrate). The layer and/or the substrate are printed by piezoelectric inkjet technique. The layer and/or substrate comprise multi-spectral absorption element. The surface of the layer and/or substrate is treated by chemical and/or laser procedure. The absorbent layer comprises a non-silicon layer, amorphous silicon, inorganic and/or organic material.    USE - The method is useful for producing solar energy based on nanoparticles.    ADVANTAGE - The method ensures rapid, continuous and cost effective production of solar energy with high yield in an eco-friendly manner thus improving the energy efficiency of the multispectral photovoltaic cells.    DETAILED DESCRIPTION - The method comprises attaching a layer, other substrate layers and/or substrate by grafting of particles forming adhering points for the layer or substrate to be deposited or printed. The received layer is an absorbent layer (on the substrate). The layer and/or the substrate are printed by piezoelectric inkjet technique. The layer and/or substrate comprise multi-spectral absorption element. The surface of the layer and/or substrate is treated by chemical and/or laser procedure. The absorbent layer comprises a non-silicon layer, amorphous silicon, inorganic material, organic material and/or oligomeric group, microcrystalline silicon, inorganic nanofilament dispersed in an organic matrix, inorganic tetrapods dispersed in an organic matrix, nanomaterials such as quantum box, ionic conductive polymer gels, sol-gel nanocomposite containing an ionic liquid, ionic conductors, organic conductive holes with low molecular weight, 60C and/or other tiny molecules, and/or a nanostructured layer having template and/or a porous inorganic matrix filled with organic material (doped or undoped), a cellular polymer architecture/mixture and/or a cellular microcrystalline silicon architecture. An INDEPENDENT CLAIM is included for a device for producing solar energy based on nanoparticles.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a roll-to-roll production line for producing solar energy.    Unwinding device (1-1)    Block (1-2)    Grafting step (1-3)    Printing step (1-4)    Drying step. (1-5)