“…It is reported that the plasmon excited electrons of metal transfer to the conduction band of semiconductor, which is called direct electron transfer instead of resonant energy transfer [55]. However, in Ag/ZnO, the CB level of ZnO is more negative than the work function of Ag (4.26 eV), so the electron transfer from Ag to ZnO is energetically undesirable [32,55]. previously published works [50,51,54].…”