【作者】 马姣民；

【导师】 郜小勇；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2011， 硕士

【摘要】 本文利用射频磁控溅射(RF sputtering)技术,通过调制氧氩比(OFR= [O2]/[Ar]).衬底温度(T)和溅射功率(P)在玻璃衬底上制备了一系列单相Ag2O薄膜,并重点研究了不同工艺参数对Ag2O薄膜的微结构和光学性质的影响。利用X射线衍射谱和扫描电子显微镜对薄膜的微结构和表面特性进行了表征；利用分光光度计、椭圆偏振光谱技术和经典的单振子模型研究了Ag2O薄膜的光学性质,并拟合了与薄膜光学性质相关的光学常数等物理参数。在此基础上,通过构建通用振子模型研究了薄膜的微结构和光学性质之间的关系。主要的创新性研究结果如下：1.用RF sputtering技术制备了单相的Ag2O薄膜,使氧化银薄膜热分解临界温度降低到约200℃。提出将RF sputtering技术制备的单相Ag2O薄膜取代两相结构的AgxO薄膜有可能有效解决AgxO在短波方向的光存储和磁光存储应用瓶颈。2.采用RF sputtering技术,在T=200℃,OFR=0.667, P=200 W条件下制备了具有最好的<111>择优取向的单相Ag2O薄膜。随着P从120 W增大到240 W,薄膜的<111>方向上的平均晶粒尺寸会先从22.92 nm增大到27.96nm,然后再减小到26.66 nm,薄膜表面结构会从均匀、致密的表面结构向疏松、多孔结构的演变。3.采用RF sputtering技术,在P=200 W,OFR=0.667条件下通过改变T制备了一系列的Ag2O薄膜。T≤200℃时,制备的Ag2O薄膜均呈现出良好的<111>择优取向。随着T从100℃升高到225℃,Ag2O薄膜的结晶趋于变差。随着T的增大,Ag2O薄膜<111>方向上的平均晶粒尺寸从17.79 nm增加到30.60 nm.。薄膜的表面结构明显呈现了从均匀、致密的表面结构向疏松、混乱沟壑结构的演变。薄膜透明区的反射率和透射率随T的逐渐增大逐渐降低,而吸收率逐渐增高。随着T的增大,制备的Ag2O薄膜的光学带隙Eg,opt总体从3.25 eV减小到2.77 eV。4.利用RF sputtering技术,在T=200℃,P=200 W的条件下通过改变OFR制备了一系列的Ag2O薄膜,其中OFR=0.667条件下制备的单相Ag2O薄膜的质量最好,该薄膜具有明显的<111>择优取向。随着OFR的增加,薄膜的<111>方向的平均晶粒尺寸从23.65 nm增大到28.41nm,而薄膜的电导率在不断地F降大小保持在10-4的数量级。薄膜在近红外区的透射率均超过70%,在可见光区域急剧下降。薄膜的光学带隙在3.266 eV和3.107 eV之间。5借助测量的椭圆偏振光谱,并利用通用振子模型(包括1个Tauc-Lorentz振子和2个Lorentz振子)拟合了单相Ag2O膜的厚度、折射率、消光系数和光学带隙等参数。结果显示,正常色散发生在2.13 eV以下,反常色散发生在3.3 eV以上,与等离子振动频率一致。Eo和Ed别是单振子的能量和散射能,拟合的单振子模型参数Eo和Ed别为3.546 eV和13.367 eV。表明由射频磁控溅射法制备的Ag2O膜为离子型合物。根据单一谐振子模型,计算的带隙参数Ea等离子频率(?)ωρ别为0.89 eV和3.44 eV。更多还原

【Abstract】 In this thesis, using radio-frequency magnetron reactive sputtering technique (RF sputtering), a series of single-phased Ag2Ofilms were deposited on glass substrates by changing the oxygen flux rate (OFR=[O2]/[Ar]), substrate temperature (T) and sputtering power (P). Effects of the OFR, T and P were intensively studied on the films’microstructure and optical properties. The film’s microstructure and surface morphology were characterized by X-ray diffractometry and scanning electron microscopy, whereas the films’optical properties were studied by spectrophotometry, spectroscopic ellipsometry and classical single-oscillator model. Some physical parameters related to the film’s optical properties were fitted in terms of single-oscillator model by using the measured spectroscopic ellipsometric parameters, based on which the relationship between the film’s microstructure and optical properties was studied by constructing the general oscillator model. Some creative research results are listed as follows.1. Single-phased Ag2O film was successfully deposited by RF sputtering technique and lowered the critical thermal decomposition to about 200℃. This may deal with the bottleneck of the film’s application in optical and magneto-optical storage.2. Using RF sputtering technique, single-phased Ag2O film with (111) preferential orientation was deposited at T=200℃, OFR=0.667 and P=200 W. With increasing the P from 120 to 240 W, the average grain size along (111) orientation increases from 22.92 to 27.96 nm and then decreases to 26.66 nm. The film’s surface shows an evolution from even and compact to loose and porous structure.3. Using RF sputtering technique, a series of Ag2O films were deposited at OFR= 0.667 and P=200 W by modifying the T values. The Ag2O films deposited at the T below 200℃are (111) preferentially oriented. The crystallization tends to become poor with increasing the T values from 100 to 225℃. Especially, the Ag2O film deposited at T=225℃lost the (111) preferential orientation. Correspondingly, the film’s surface morphology obviously evolves from the uniform and compact surface structure to the loose and gullied surface structure. With increasing the T values, the film’s transmissivity and reflectivity in transparent region are gradually reduced, while the absorptivity gradually increases. The film’s optical energy gap (Eg opt) largely decreases from 3.25 eV to 2.77 eV as the T increases.4. A series of silver oxide (AgxO) films were deposited on glass substrates at T 200℃and P=200 W by RF sputtering using different OFR values. The Ag2O film deposited at OFR=0.667 is best crystallized and (111) oriented. The average grain size along Ag2O (111) orientation increases from 23.65 nm to 28.41 nm with, while the film’s conductivity with an order of -4 largely decreases with increasing the OFR. The film’s transmissivity in near infrared region surpasses 70%, while sharply decreases in the visible region. The film’s E g, dir changes in the range from 3.266 eV to 3.107 eV.5. Using the measured spectroscopic ellipsometry plus single-oscillator model, the film thickness, refractive index, extinctive coefficient, plasma oscillator frequency and energy gap of the single-phased Ag2O film is fitted using general oscillator model(include one Tauc-Lorentz oscillator and two Lorentz oscillators).. The result indicate that the normal optical dispersion occurs below 2.13 eV, and the abnormal optical dispersion occurs above 3.3 eV, which corresponds to the plasma oscillator frequency. The fitted E0 and Ed closely related to crystalline structure and ionicity are 3.546 eV and 13.367 eV, respectively, indicating that the cubic single-phased Ag2O film as-deposited by RF sputtering falls into the ionic class. The fitted optical engergy gap and plasma oscillation frequency in terms of single-oscillator model are 0.89 eV and 3.44 eV, respectively.更多还原