EP07.03.08 : Optimizing of Switching Properties of Polycrystalline VO2 Films by Co-Doping with Hf and Nb in THz Range

5:00 PM–7:00 PM Apr 3, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Chunhui Ji1 Zhiming Wu1 Jun Wang1

1, University of Electronic Science and Technology of China, Chengdu, , China

Owing to their dramatic ultrafast reversible metal insulator transition (MIT), vanadium dioxide (VO2) thin films are of significant interest for numerous potential applications, such as ultrafast electro-optical switching devices, Mott field-effect transistors, and optical waveguides [1-3]. Since THz transmittance dramatically changes across this first-order structural phase transition, it indicates good application potential for THz device. In general, VO2 film has a high phase transition temperature and a wide hysteresis width, especially on silicon substrates, which restrict the development of VO2-based devices. For practical application the MIT properties have to be tailored. In this work, We have deposited undoped, Hf doped VO2 and Hf-Nb co-doped VO2 thin film on high-purity single-crystal Si substrates by DC reactive magnetron sputtering method and investigated their switching properties at THz range. Finally, the excellent combined switching properties were obtained by Hf and Nb co-doping. In particular, the Hf-Nb codoped VO2 film exhibits a small hysteresis width around 5.8 °C, a low phase transition temperature down to 47.1 °C and a high THz transmission modulation depth of 84%, which is promising for THz modulation applications [4]. This work provides a feasible solution to the design and fabrication of VO2 films with suitable MIT properties for THz device.

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