Nanocrystal-size control of electrodeposited nanocrystalline semiconductorfilms by surface capping

The crystal size of nanocrystalline CdS and CdSe films, electrodeposited fr om dimethyl sulfoxide solutions containing a Cd salt and elemental S or Se, is shown to depend on the nature of the anion of the Cd salt, Relatively s trongly adsorbing anions, such as chloride, result in a smaller nanocrystal size than relatively nonadsorbing anions such as perchlorate. This differe nce in nanocrystal size is explained by blocking (or capping) of the growin g crystals by the adsorbed ions. Very strongly adsorbing species, such as a lkyl phosphines, result in even smaller crystal size (3.5 nm average diamet er). (C) 2000 The Electrochemical Society. S0013-4651(99)07-036-6. All righ ts reserved.