School of Materials Engineering, Purdue University , West Lafayette, Indiana 47907-2045, United States.
ACS Appl Mater Interfaces. 2017 Feb 15;9(6):5319-5327. doi: 10.1021/acsami.6b13217. Epub 2017 Feb 3.
Vanadium dioxide (VO) thin films with controlled thicknesses are deposited on c-cut sapphire substrates with Al-doped ZnO (AZO) buffer layers by pulsed laser deposition. The surface roughness of AZO buffer layers is varied by controlling oxygen pressure during growth. The strain in the VO lattice is found to be dependent on the VO thickness and the VO/AZO interface roughness. The semiconductor-to-metal transition (SMT) properties of VO thin films are characterized and the transition temperature (T) is successfully tuned by the VO thickness as well as the VO/AZO interface roughness. It shows that the T of VO decreases with the decrease of film thickness or VO/AZO interface roughness. Other SMT properties of the VO films are maintained during the T tuning. The results suggest that the strain tuning induced by AZO buffer provides an effective approach for tuning T of VO continuously.
采用脉冲激光沉积法在掺铝氧化锌（AZO）缓冲层的 c 切蓝宝石衬底上沉积了具有可控厚度的二氧化钒（VO）薄膜。通过控制生长过程中的氧压来改变 AZO 缓冲层的表面粗糙度。发现 VO 晶格中的应变取决于 VO 的厚度和 VO/AZO 界面粗糙度。对 VO 薄膜的半导体-金属转变（SMT）特性进行了表征，并通过 VO 的厚度以及 VO/AZO 界面粗糙度成功地调节了转变温度（T）。结果表明，VO 的 T 随着薄膜厚度或 VO/AZO 界面粗糙度的减小而降低。在 T 调节过程中，VO 薄膜的其他 SMT 特性得以保持。结果表明，由 AZO 缓冲层引起的应变调节为连续调节 VO 的 T 提供了一种有效的方法。
