MBE法制备VO_2薄膜及其中红外调制深度测量  

VO_2 Thin Films Prepared by MBE and Measurements of Mid-infrared Modulation Depth

作　　者：刘志伟 路远 侯典心[1,2,3] 邹崇文 LIU Zhi-wei;LU Yuan;HOU Dian-xin;ZOU Chong-wen(Electronic Countermeasures Institute of National University of Defense Technology,Hefei 230037,China;Infrared and Low Temperature Plasma Key Laboratory of Anhui Province,Hefei 230037,China;State Key Laboratory of Pulsed Power Laser Technology,Hefei 230037,China;National Synchronous Radiation Laboratory of University of Science and Technology of China,Hefei 230037,China)

机构地区：[1]国防科技大学电子对抗学院,安徽合肥230037 [2]红外与低温等离子体安徽省重点实验室,安徽合肥230037 [3]脉冲功率激光技术国家重点实验室,安徽合肥230037 [4]中国科学技术大学国家同步辐射实验室,安徽合肥230037

出　　处：《发光学报》2018年第7期942-947,共6页Chinese Journal of Luminescence

基　　金：脉冲功率激光技术国家重点实验室主任基金(SKL2013ZR03)资助项目~~

摘　　要：为了给VO_2薄膜在定向红外对抗系统防护方面的应用提供理论依据,我们用透过率调制深度表征VO_2薄膜在中红外波段的相变特性。本实验利用分子束外延法(MBE)制备VO_2外延单晶薄膜,经XRD、AFM表征,发现其具有(020)择优取向、纯度较高,薄膜表面平整、均匀且致密。经VU-Vis-IR测量发现其近红外透过率相变特性显著,但在紫外和可见光范围内透过率相变特性较不明显。然后我们对制备时间为30 min、40min的两组薄膜分别进行25~70℃的升温和降温实验,观察其对波长为3 459 nm、脉宽50 ns、重频50 k Hz、功率密度0.14 W/cm2的中红外激光的透过率变化,并比较两组薄膜的温滞曲线特性。实验发现它们对中红外透过率的调制深度均可达60%以上,前者比后者对中红外的调制深度高出约4%。这说明利用分子束外延法制备的VO_2单晶薄膜具有良好的中红外调制特性,且调制深度和膜厚有关。进一步表明了利用VO_2薄膜实现中红外激光防护具有一定的可行性。In order to provide the theoretical basis for the application of VO 2 thin films to anti-directional infrared countermeasures system, the phase transition characteristics of VO 2 thin films in the infrared band were characterized by the transmittance modulation depth. At first, VO 2 epitaxial mono crystalline thin films were prepared by molecular beam epitaxy（MBE）, and then characterized by X-ray diffraction（XRD）, atomic force microscope（AFM）. It is found that it has （020） preferential orientation, high purity VO 2 in the thin films, the surface of thin films is smooth, uniform and dense. The near infrared transmittance phase transmittance property is found to be outstanding by VU-Vis-IR measurement, however, it is less obvious in ultraviolet and visible light. We took an experiment that transmittance variation for mid-infrared from 25 to 70 ℃ temperature rising and cooling process based on two groups of VO 2 prepared for 30 min and 40 min, respectively. The mid-infrared laser was used in the experiment with 3 459 nm wavelength, 50 ns pulse width, 50 kHz repetition frequency, and 0.14 W/cm 2 power density. The two temperature hysteresis curves were compared. It is found that the transmittance modulation depth of mid-infrared of them both can reach over 60%, and the former group is about 4% higher than the latter group in transmittance modulation depth in mid-infrared. This indicates that the VO 2 mono crystalline films prepared by the molecular beam epitaxial method have good mid-infrared transmittance modulation characteristics, and the modulation depth is related to film thickness. It is further demonstrated that it is feasible to put VO 2 thin films into anti-directional infrared countermeasures system.

关 键 词：分子束外延 VO2薄膜 透过率调制深度 中红外激光防护 

分 类 号：O434.14[机械工程—光学工程]