Growth and electron field emission of ZnO nanorods on diamond films

► The growth evolution of ZnO nanorods (NRs) on diamond films has been investigated. ► The size of diamond grains determines a certain extent the diameter of the ZnO NRs. ► The mechanism for the influence of diamond grain size on the features of ZnO NRs has been studied. ► The electron field emission properties of the ZnO NRs/diamond system have been significantly improved with respect to pure diamond film.