Gate‐Induced Massive and Reversible Phase Transition of VO₂ Channels Using Solid‐State Proton Electrolytes

Abstract

The use of gate bias to control electronic phases in VO 2 , an archetypical correlated oxide, offers a powerful method to probe their underlying physics, as well as for the potential to develop novel electronic devices. Up to date, purely electrostatic gating in 3-terminal devices with correlated channel shows the limited electrostatic gating efficiency due to insufficiently induced carrier density and short electrostatic screening length. Here massive and reversible conductance modulation is shown in a VO 2 channel by applying gate bias V G at low voltage by a solid-state proton (H + ) conductor. By using porous silica to modulate H + concentration in VO 2 , gate-induced reversible insulator-tometal (I-to-M) phase transition at low voltage, and unprecedented two-step insulator-to-metal-to-insulator (I-to-M-to-I) phase transition at high voltage are shown. V G strongly and efficiently injects H + into the VO 2 channel without creating oxygen deficiencies; this H + -induced electronic phase transition occurs by giant modulation (≈7%) of out-of-plane lattice parameters as a result of H + -induced chemical expansion. The results clarify the role of H + on the electronic state of the correlated phases, and demonstrate the potentials for electronic devices that use ionic/electronic coupling.

Electrolyte‐Gated Synaptic Transistor with Oxygen Ions

“…Since the ionic liquid contains an amount of trace water, the hydrolysis reaction will occur under high gate voltages. The required oxygen ions can come from this hydrolysis . When a stimulus spike is applied on the presynaptic neuron, it triggers an excitatory postsynaptic current (EPSC) in the SCO channel.…”

Recent Progress on Vanadium Dioxide Nanostructures and Devices: Fabrication, Properties, Applications and Perspectives

“…As shown in Figure 19 h, a reversible MIT of VO 2 is demonstrated from the temperature-dependent plate resistance ( R s ) in VO 2 -based ILs FET at different gate voltages. What is more, Jo et al [ 143 ] used solid-state proton electrolyte to achieve a reversible MIT of VO 2 at room temperature. A large number of H + ions were effectively injected into VO 2 channel under gate bias voltage without oxygen defects.…”

“…As we know, hydrogen is the smallest and lightest atomic element, which can effectively insert or remove the gap position of VO 2 , thereby modulating the MIT behavior [ 143 , 160 ]. The research results of Yoon et al [ 160 ] demonstrated that VO 2 stabilizes in the metal phase at a low hydrogen concentration, and the hydrogenated insulating phase (note as HVO 2 phase) occurs again at a high hydrogen concentration.…”

Conductivity Modulation by CaVO₃-based All-solid-state Redox Transistor with Ion Transport of Li⁺ or H⁺

“…Recently, in situ control of electronic carrier through ion transport in nanoscale has been attracting attention for nanoelectronics devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Physical properties such as electronic conductivity, magnetoresistance and superconducting critical temperature were tuned by the similar method [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The redox transistor employs electrochemical carrier doping by electrochemical reduction and oxidation (redox) due to the ion transport.…”