A process for preparing stacks of metal chalcogenide flakes includes: (a) reacting together a source of the metal atom of the target metal chalcogenide with a source of the chalcogenide atom of the target metal chalcogenide, in the presence of a spacer, so as to produce flakes of the metal chalcogenide; (b) depositing metal chalcogenide flakes obtained using step (a) onto a substrate to form a stack of assembled metal chalcogenide flakes, wherein the spacer contains an alkyl chain linked to a functional group able to bond to the metal chalcogenide surface, said alkyl chain having a length of less than 18 carbon atoms, preferably between 6 and 14 carbon atoms.