PNNL

Abstract

Manipulating insulator-metal transition (IMT) in strongly-correlated materials draws wide-range research interests due to its promising applications such as memories, electrochromic windows, optical modulators1–3. Electric-field-controlled hydrogenation through ionic liquid gating represents a unique pathway to obtaining IMT with associated electron filling, which however faces the technical challenges of integrating capability and switching speed. Here we demonstrate a local electric-field control of reversible hydrogenation into VO2 with tunable IMT using scanning probe microscopy. The Pt-coated tip serves as an efficient H2 catalyzer in contact with the sample, and the positively-biased voltage leads to sustainable hydrogenation with a nanoscale structural transformation from insulating VO2 into conducting HxVO2. Remarkably, the dehydrogenation process can be elaborately obtained with a negatively-biased tip, which turns the insulating state back. This work demonstrates a local and reversible electric-field-controlled IMT through hydrogenation and points to a promising pathway to engineer oxide electronic devices through direct circuit printing.