Dielectric/Semiconductor Interfacial p-Doping: A New Technique to Fabricate Solution-Processed High-Performance 1 V Ambipolar Oxide Transistors

Herein, dielectric/semiconductor interfacial p-doping is used to develop a high-carrier-mobility and balanced ambipolar tin oxide (SnO2) thin-film transistor (TFT). To introduce this interfacial doping, TFTs are fabricated by using two different ion-conducting oxide dielectrics containing trivalent atoms. These ion-conducting dielectrics are LiInO(2)and LiGaO(2)containing a mobile Li(+)ion that reduces the operating voltage of these TFTs to <= 2.0 V. During SnO(2)thin film deposition, the interfacial SnO(2)layer is p-doped by an In or Ga atom of the gate dielectric and therefore, hole conduction is facilitated in the channel of the TFT. To realize this interfacial doping phenomenon, a reference TFT is fabricated with a Li(2)ZnO(2)dielectric that contains a divalent zinc atom. Comparative electrical data indicate that TFTs with LiInO(2)and LiGaO(2)dielectrics are ambipolar in nature, whereas the TFT with a Li(2)ZnO(2)dielectric is a unipolar n-channel transistor, corroborating the interfacial doping of SnO2. Most interestingly, using a LiInO(2)dielectric, a 1.0 V balanced ambipolar TFT with high electron and hole mobility values of 7 and 8 cm(2) V-1 s(-1), respectively, can be fabricated, with an on/off ratio > 10(2)for both operations. The TFT with a LiInO(2)dielectric is utilized successfully to fabricate a low-voltage complementary metal-oxide-semiconductor (CMOS) inverter.