Improving phase transition temperature of VO2 via Ge doping:a combined experimental and theoretical study

• 作者: Lin Wang Yu-Qi Hao Wei Ma Sen Liang
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 1337-1346
• 页数: 10页
• 语种: 英文

摘要

Enhancing the semiconductor-metal phase transition temperature(TSMT)of VO2 is of great conse-quence for further exploring the potential applications of VO2 at elevated temperatures.In this study,Ge4+-doped VO2(GexV 1-xO2)samples were prepared by the hydrothermal and annealing approach.X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),differential scanning calorimetry(DSC)and resistivity-temperature(R-T)analyses were used to inves-tigate the influence of Ge doping on the lattice structures and phase transition properties of GexV 1-xO2 samples.We found that the lattice parameter of GexV1-xO2 decreased with the Ge concentration increasing from 2 at％to 18 at％,which was further supported by density functional theory(DFT)-based first-principle simulations.TSMT firstly increased from 64.5 to 73.0℃at 8 at％Ge and then decreased to 71.5℃at higher Ge concentration.Further-more,DFT analysis revealed that the impact of lattice distortion induced by Ge doping rather than the changes in electronic structure is more pronounced on modulating TSMT of GexV 1-xO2.The present work has pointed out the direction that the TSMT could be enhanced and illustrated the physical reason behind the regulation of TSMT in ions-doped VO2 systems.