Threshold voltage manipulation of ZnO-graphene oxide hybrid thin film transistors via Au nanoparticles doping

In order to fabricate a complementary inverter, precise control of the threshold voltages for n-type semiconductor based thin film transistors (TFTs) is highly required. Here we provided a facile methodology for controlling the threshold voltage of ZnO-based TFTs. Chemically-derived graphene oxide (GO) and Au-decorated GO (Au-GO) flakes were hybridized with solution-processed ZnO thin films to control electron injection determined by the workfunction difference between ZnO and GO or Au-GO. As a result, the threshold voltages for the ZnO, GO/ZnO, and Au-GO/ZnO TFTs were 24 ± 3 V, −11 ± 4 V, and 63 ± 5 V, respectively, which determine depletion or enhancement mode TFTs without any significant change in the field effect mobility and on/off ratio.