講演情報
[21p-D903-15]Determining the in-plane crystal arrangement of VO2 film on CVD-grown hBN sheet using transmission electron microscopy
〇(D)Boyuan Yu1, Shingo Genchi1, Haobo Li1,2, Azusa N. Hattori1,2, Satoru Fukamachi3, Hiroki Ago3, Hidekazu Tanaka3 (1.SANKEN, Osaka Uni, 2.IOTRI, Osaka Uni, 3.GIC, Kyushu Uni)
キーワード：
VO2、hBN、in-plane arrangement
Vanadium dioxide (VO2) is a strongly correlated metal oxide that undergoes a significant resistance change during the metal-insulator transition (MIT) around room temperature. It has attracted considerable research interest for its potential applications in electronic devices such as sensors, switches, and terahertz emitters. While VO2 thin films are typically grown on single crystal oxide substrates, our group has recently achieved the growth of VO2 films on two-dimensional (2D) layered hexagonal boron nitride (hBN) beyond the crystal lattice matching at the interface. This enables the use of flexible and transferable hBN as a substrate, expanding the potential device applications of VO2 films. However, the growth mechanism of VO2 films on hBN sheets remains unclear, particularly considering the weak van der Waals interaction at the surface of 2D layered hBN.
In this study, we fabricated a VO2 film on a chemical vapor-deposited (CVD) hBN sheet and investigated the in-plane crystal arrangements of the VO2 film using transmission electron microscopy (TEM). The VO2 film, with a thickness of 30 nm, was epitaxially grown on a large-sized (5×5 mm2 ) CVD-hBN sheet on an SiO2/Si substrate using pulsed laser deposition. By leveraging the transferability of hBN, we prepared freestanding VO2/hBN membrane samples with sub-millimeter sizes using a novel transfer technique. Room temperature top-view TEM observations were performed on this membrane. Systematic TEM observations of both the pristine hBN sheet and the VO2/hBN membrane sample demonstrated that the in-plane directions [120] and [100] of hBN were parallel to the [1-10] and [001] directions of VO2, respectively. In our presentation, we will present the elucidation of the in-plane atomic arrangement and discuss the epitaxial growth mechanism of the VO2 film on an hBN sheet.
In this study, we fabricated a VO2 film on a chemical vapor-deposited (CVD) hBN sheet and investigated the in-plane crystal arrangements of the VO2 film using transmission electron microscopy (TEM). The VO2 film, with a thickness of 30 nm, was epitaxially grown on a large-sized (5×5 mm2 ) CVD-hBN sheet on an SiO2/Si substrate using pulsed laser deposition. By leveraging the transferability of hBN, we prepared freestanding VO2/hBN membrane samples with sub-millimeter sizes using a novel transfer technique. Room temperature top-view TEM observations were performed on this membrane. Systematic TEM observations of both the pristine hBN sheet and the VO2/hBN membrane sample demonstrated that the in-plane directions [120] and [100] of hBN were parallel to the [1-10] and [001] directions of VO2, respectively. In our presentation, we will present the elucidation of the in-plane atomic arrangement and discuss the epitaxial growth mechanism of the VO2 film on an hBN sheet.