基于FTO/VO_2/FTO结构的VO_2薄膜电压诱导相变光调制特性  

Optical modulation characteristics of VO_2thin film due to electric field induced phase transition in the FTO/VO_2/FTO structure

作　　者：郝如龙 李毅[1,2] 刘飞[1] 孙瑶[1] 唐佳茵[1] 陈培祖 蒋蔚[1] 伍征义 徐婷婷[1] 方宝英[1] 王晓华[1,3] 肖寒[1] 

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093 [2]上海市现代光学系统重点实验室,上海200093 [3]上海电力学院电子与信息工程学院,上海200090

出　　处：《物理学报》2015年第19期319-327,共9页Acta Physica Sinica

基　　金：国家高技术研究发展计划"863"计划(批准号:2006AA03Z348);教育部科学技术研究重点项目(批准号:207033);上海市科学技术委员会科技攻关计划(批准号:06DZ11415);上海市教育委员会科技创新重点项目(批准号:10ZZ94);上海领军人才培养计划资助项目(批准号:2011-026)资助的课题~~

摘　　要：采用直流磁控溅射和后退火工艺在掺氟的SnO2(FTO)导电玻璃衬底上制备VO2薄膜,研究了不同退火时间和不同比例的氮氧气氛对VO2薄膜性能的影响,对VO2薄膜的结晶取向、表面形貌、表面元素的相对含量和透过率随波长变化进行了测试分析,结果表明在最佳工艺条件下制备得到了组分相对单一的VO2薄膜.基于FTO/VO2/FTO结构在VO2薄膜两侧的透明导电膜上施加电压并达到阈值电压时,观察到了明显的电流突变.当接触面积为3 mm×3 mm时,阈值电压为1.7 V,阈值电压随接触面积的增大而增大.与不加电压的情况相比,FTO/VO2/FTO结构在电压作用下高低温的红外透过率差值可达28%,经反复施加电压,该结构仍保持性能稳定,具有较强的电致调控能力.VO2 thin films have been studied for their semiconductor–metal reversible transition from the monoclinic to the rutile structure, where the electrical and optical properties undergo a drastic change by increasing the temperature or by applying a voltage. VO2 film is becoming a promising material for optical switch, optical storage, optical modulator, smart window, and micro-bolometer. The preparation procedures of the FTO/VO2/FTO structure in detail are as follows：First, the F-doped SnO2 conductive glass （FTO） substrates are cleaned sequentially in acetone, ethanol, and deionized water for 10 min using an ultrasonic cleaning equipment at a frequency of 20 kHz. When the FTO substrates was cleaned, they are dried with nitrogen. Second, the dried FTO substrates are placed in the chamber of a DC magnetron sputtering system equipped with a high-purity metal target of V （99.9%）. After argon （99.999%） of 80 sccm flux was discharged with the current of 2 A and the voltage of 400 V for 2 min, the vanadium films are deposited on the FTO substrates. Third, the prepared vanadium films are annealed for different annealing time in an atmosphere composed of different proportions of nitrogen-oxygen. Then another layer thickness of 350 nm of FTO conductive film is deposited on the VO2 thin film by using the plasma enhanced chemical vapor deposition method. Finally, different sizes of the FTO/VO2/FTO structure are prepared by using photolithography and chemical etching processes. The effect of different annealing time and different proportions of nitrogen-oxygen atmosphere on the VO2 thin films has been studied. X-ray diffraction （XRD）, scanning electron microscope （SEM）, atomic force microscope （AFM）, X-ray photoelectron spectroscopy （XPS） and spectrophotometer are then used to test and analyze the crystal structure, surface morphology, surface roughness, the relative content of the surface elements, and transmittance of the VO2/FTO composite films. Results show that a relatively single component V

关 键 词：VO2/FTO 直流磁控溅射 阈值电压 电致相变 

分 类 号：O484.4[理学—固体物理]