Electrical Switching in Semiconductor-Metal Self-Assembled VO2 Disordered Metamaterial Coatings

Abstract

As a strongly correlated metal oxide, VO2 inspires several highly technological applications. The challenging reliable wafer-scale synthesis of high quality polycrystalline VO2 coatings is demonstrated on 4” Si taking advantage of the oxidative sintering of chemically vapor deposited VO2 films. This approach results in films with a semiconductor-metal transition (SMT) quality approaching that of the epitaxial counterpart. SMT occurs with an abrupt electrical resistivity change exceeding three orders of magnitude with a narrow hysteresis width. Spatially resolved infrared and Raman analyses evidence the self-assembly of VO2 disordered metamaterial, compresing monoclinic (M1 and M2) and rutile (R) domains, at the transition temperature region. The M2 mediation of the M1-R transition is spatially confined and related to the localized strain-stabilization of the M2 phase. The presence of the M2 phase is supposed to play a role as a minor semiconducting phase far above the SMT temperature. In terms of application, we show that the VO2 disordered self-assembly of M and R phases is highly stable and can be thermally triggered with high precision using short heating or cooling pulses with adjusted strengths. Such a control enables an accurate and tunable thermal control of the electrical switching.

The Control of Transition Behavior of VO2 Film Deposited on Sapphire (0001) Substrate by the Organic Polymer‐Assisted Thermal Deposition

“…. These interesting properties of VO 2 make the material as a good candidate of variety practical applications such as field effect transistors, switches, sensors, smart window, etc …”

Visible Thermochromism in Vanadium Pentoxide Coatings

“…Surprisingly, the intrinsic thermochromic behavior of V 2 O 5 seems to be overlooked. It should be cautiously noted that another oxide of vanadium, namely VO 2 , is extensively studied for its thermochromic behavior in the infrared spectral range, 42 but we strictly restrict this study to V 2 O 5 for all purposes. In this work, we shed light on the intrinsic visible thermochromism in pure and chemically doped vanadium pentoxide (V 2 O 5 ) thin films at elevated temperatures.…”

Vanadium Oxide as a Key Constituent in Reconfigurable Metamaterials

“…The disordered metamaterial state of VO 2 is very stable [34], as long as the surface is maintained at a constant temperature within the hysteresis region. The phase fraction of semiconducting to metallic remains undisturbed.…”

“…Furthermore, the transition characteristics were shown to be immune to the cycling rate. The stability of the metamaterial state was observed upon an extended Raman mapping of the mixed phase region over 100 hrs [34].…”