Switching Enhancement in Copper Oxide Thin-Film Transistors via Molybdenum Trioxide Buffering and Nitrogen Doping

Switching characteristics of copper oxide (Cu2O) thin-film transistors (TFTs) were enhanced by buffering both sides of the channel with a thin layer of sputtered molybdenum trioxide (MoO3). On the top side, the thin MoO3 layer was capable of controlling the back-channel phase by forming a high-resistance surface-path and hence reducing the drain off-current. While on the bottom side, the MoO3 film worked as a passivation layer at the (semiconductor/dielectric) interface which helped in reducing the interfacial states density D-it by one order of magnitude. By optimizing the nitrogen doping conditions and harnessing the bilayer channel scheme, switching characteristics were enhanced even more. Our best double-buffered bilayer TFT achieved a subthreshold swing of 0.14 V dec(-1), an on/off current ratio (I-on/I-off) of 2.7 x 10(6), and a field-effect mobility (mu(FE)) of 0.11 cm(2) V-1 s(-1), a considerable enhancement in performance compared to that of non-doped non-buffered Cu2O TFTs.

Automated summary

The switching characteristics of copper oxide (Cu2O) thin-film transistors (TFTs) were improved by buffering both sides of the channel with a thin layer of sputtered molybdenum trioxide (MoO3). The top MoO3 layer controlled the back-channel phase and reduced the drain off-current, while the bottom MoO3 film acted as a passivation layer at the semiconductor/dielectric interface, reducing the interfacial states density D-it. By optimizing the nitrogen doping conditions and using the bilayer channel scheme, the switching characteristics were further enhanced.