NOVELTY - A method involves: a) providing a first mixture comprising at least one nanoparticle precursor and at least one first solvent for the nanoparticle precursor; b) providing a second mixture comprising at least one reactive moiety reactive for the nanoparticle precursor and at least one second solvent for the reactive moiety; c) combining the first and second mixtures in presence of a surface stabilizing agent to form nanoparticles; d) formulating the nanoparticles into an ink or paste; and e) forming a film with the ink or paste on a silicon substrate.    USE - For making a silicon based device i.e. a photovoltaic device (claimed) e.g. solar cells.    ADVANTAGE - The method allows the annealing process to take place at a lower temperature, preferably lower than 500 degrees C and more preferably 300 degrees C. Moreover, an intermediate adhesion layer is not needed between the nanoparticles and silicon and also provides versatility in selecting nanoparticle composition and size. The method also allows for fabricating discrete particles with size in nanometer range and with a low melting temperature.    DETAILED DESCRIPTION - A method involves: a) providing a first mixture comprising at least one nanoparticle precursor and at least one first solvent for the nanoparticle precursor, where the nanoparticle precursor comprises a salt comprising a cation comprising a metal; b) providing a second mixture comprising at least one reactive moiety reactive for the nanoparticle precursor and at least one second solvent for the reactive moiety, where the second solvent phase separates when it is mixed with the first solvent; c) combining the first and second mixtures in the presence of a surface stabilizing agent, where upon combination the first and second mixtures phase-separate and nanoparticles are formed; d) formulating the nanoparticles into an ink or paste; and e) forming a film with the ink or paste on a silicon substrate. An INDEPENDENT CLAIM is included for a device, comprising an ink or paste disposed on a semiconductor material, where the ink or paste comprises first conductive nanoparticles and further comprises second additive nanoparticles different from the first nanoparticles.