A process for producing nanoparticles incorporating ions selected from groups 13, 16, and 11 or 12 of the periodic table is described. The process comprises effecting conversion of a nanoparticle precursor composition comprising said group 13, 16, and 11 or 12 ions to the material of the nanoparticles in the presence of a selenol compound. A process for fabricating a thin film comprising nanoparticles incorporating ions selected from groups 13, 16, and 11 or 12 of the periodic table is also described, as well as a process for producing a printable ink formulation comprising said nanoparticles.