掺锗提高VO2薄膜的相变温度机理研究

二氧化钒(VO₂)作为一种长久以来备受关注的新型可逆相变材料,发展潜力巨大,其相变温度(T_MIT)的调控一直是研究热点。本文主要利用锗离子作为掺杂离子探索其对VO₂薄膜T_MIT的影响,并尝试解释其内部作用机理。在约1 cm²大小抛光的氧化铝薄片上沉积了一系列含不同比例锗离子VO₂薄膜。研究发现锗离子作为掺杂离子确实有利于T_MIT的提高(本课题T_MIT最大可达84.7 ℃)。T_MIT提高的主要原因是锗离子的引入能够强化单斜态V-V二聚体的稳定性,进而增强单斜态的稳定性,使得低温单斜态向四方金红石态转变更加困难。

Mechanism of Phase Change Temperature of VO2 Thin Films by Doping Germanium

As a new type of reversible phase change material, vanadium dioxide (VO₂) has shown great potential in development with the regulation of its phase change temperature (T_MIT) and were extensively studied. The experiment in this study focuses on exploring the effect of germanium ions on T_MIT of VO₂ thin films and trying to explain the internal mechanism. A series of VO₂ films containing different ratios of germanium ions were deposited on polished alumina sheets. The characterization results show that germanium ions contribute to increasing T_MIT (maximum T_MIT is 84.7 ℃). The main reason for this increase is that germanium ion enhances the stability of monoclinic V-V dimer by increasing the stability of monoclinic V-V dimer, which makes the transition from low-temperature monoclinic state to tetragonal rutile state more difficult.