High-κ van der Waals Oxide MoO₃ as Efficient Gate Dielectric for MoS₂ Field-Effect Transistors

Two-dimensional van der Waals crystals (2D vdW) are recognized as one of the potential materials to solve the physical limits caused by size scaling. Here, vdW metal oxide MoO₃ is applied with the gate dielectric in a 2D field-effect transistor (FET). Due to its high dielectric constant and the good response of MoS₂ to visible light, we obtained a field effect transistor for photodetection. In general, the device exhibits a threshold voltage near 0 V, Ion/Ioff ratio of 10⁵, electron mobility about 85 cm² V^-1 s^-1 and a good response to visible light, the responsivity is near 5 A/W at low laser power, which shows that MoO₃ is a potential material as gate dielectric.