Manipulating the Hydrogen‐Associated Insulator‐Metal Transition Through Artificial Microstructure Engineering
Xuanchi Zhou, Xiaohui Yao, Wentian Lu, Jinjian Guo, Jiahui Ji, Lili Lang, Guowei Zhou, Chunwei Yao, Xiaomei Qiao, Huihui Ji, Zhe Yuan, Xiaohong Xu
Abstract
Abstract Hydrogen‐associated filling‐controlled Mottronics within electron‐correlated system provides a groundbreaking paradigm to explore exotic physical functionality and phenomena. Dynamically controlling hydrogen‐related phase transitions through external fields offers a promising route for designing protonic devices in multidisciplinary fields but faces high‐speed bottlenecks owing to slow bulk diffusion of hydrogens. Here, a promising pathway is presented to kinetically expedite the electronic state evolution in VO 2 system by taking advantage of artificial microstructure design. Typically, inclined domain boundary configuration and c R ‐faceted preferential orientation, simultaneously realized in VO 2 /Al 2 O 3 (102) heterostructure, significantly lower the diffusion barrier through creating an unobstructed conduit for hydrogen diffusion. As a result, the achievable switching speed through hydrogenation outperforms that of counterpart grown on widely‐utilized c ‐plane Al 2 O 3 substrate by 2–3 times, with resistive switching concurrently improved by an order of magnitude. Of particular interest, an anomalous uphill hydrogen diffusion observed for VO 2 with a diffusion highway fundamentally deviates from basic Fick's law, unveiling a deterministic role of hydrogen spatial distribution in tailoring electronic state evolution. The present work not only provides a powerful tuning knob for manipulating ionic evolution, endowing with great potential in designing advanced protonic devices, but also deepens the understanding of hydrogen‐associated insulator‐metal transition in electron‐correlated systems.