【作者】 周宏伟；

【导师】 李怀祥；

【作者基本信息】 山东师范大学 ， 物理化学， 2007， 硕士

【摘要】 氧化物透明导电薄膜以接近金属的电导率、可见光范围内高透射比、红外高反射比及其半导体特性,广泛应用于太阳能电池、平面液晶显示器（LCD）、电加热玻璃、半导体/绝缘体/半导体（SIS）异质结。其中ZnO和SnO₂是应用最广泛的两种薄膜。溶胶-凝胶法是一种制备薄膜的新方法,设备简单,易掺杂,可大面积均匀成膜。在荧光粉颗粒表面包覆上一层或多层薄膜能够使荧光粉和外界可以隔离开,提高荧光粉的分散性和稳定性,解决荧光粉由于电性和表面化学活性造成的荧光粉性能的下降,与此同时,在荧光粉表面包覆特殊材料也可以提高荧光粉的发光性能。本文围绕透明导电薄膜的制备及其应用做了以下工作:1.溶胶凝胶法制备了SnO₂:Sb和ZnO:Al薄膜,重点探讨了溶胶凝胶法制备SnO₂—ZnO复合薄膜,并且考察了其I-V特性,在较高温度下,多层复合薄膜的I-V关系逐渐偏离欧姆定律,对此现象的可能原因作出了解释。用X射线光电子能谱（XPS）分析了薄膜的表面组成,用扫面电镜（SEM）观察了薄膜的截面结构。用紫外可见分光光度计（UV-Vis）考察了薄膜的透过率。2.在含锡的干凝胶氧化过程中,首次发现了干凝胶的部分升华现象,升华产物容易成膜。把升华物质分别沉积在石英、硅基底上可以得到透明导电薄膜,实验条件:含锡的二氧化锡干凝胶0.8g作为升华源;高纯氧气（99.9%）下500℃氧化1h,基底距离升华源5cm。经X射线衍射（XRD）和X射线光电子能谱（XPS）表明,所得到的薄膜是四方相金红石结构的二氧化锡。紫外可见分光光度计（UV-Vis）测试了薄膜的透光率,在可见光区达到80%以上。用扫描电镜（SEM）和原子力显微镜（AFM）观察了薄膜的微观形貌,表明所得到的薄膜致密,晶粒大小均匀,垂直基底表面生长,薄膜厚度比较均匀。用吸收系数间接推测膜厚,厚度大约70nm,四探针测试表明薄膜的方块电阻567Ω,电阻率为2.86×10^-2Ω·cm。表现出良好的透明导电性能。3.利用含锡干凝胶部分升华产物对自制ZnS:Mn荧光粉进行包覆研究。在固定氧气流量和氧化时间的条件下,考察了干凝胶与ZnS:Mn荧光粉的质量比和氧化温度对包覆后荧光粉电阻率的影响。当干凝胶与荧光粉的质量比为3.0,氧化温度为500℃处理后荧光粉的电阻率明显下降,对包覆后的荧光粉进行了室温光致荧光（PL）光谱、X射线衍射（XRD）以及透射电镜（TEM）分析。结果表明对荧光粉的包覆,显著改变了荧光粉的导电性而荧光粉的光致发光性质和晶体结构并没有受到太大影响。更多还原

【Abstract】 Transparent and conductive oxide （TCO） films are widely used as transparent electrodes for optoelectronic devices such as touch panels, flat panel displays, liquid crystal display （LCD）, semiconductor/ insulator/ semiconductor （SIS） hetero-conjunction, and thin-film solar cells, since they have high transmittance in visible range, high reflectance in infrared range and semiconductor’s characteristics and their electrical conductivities are similar to those of metals. Recently, ZnO and SnO₂ films have received much attention because of their possibility for TCO films with excellent chemical and thermal stability in addition to high electrical conductivity and optical transparency.Comparing to other methods, sol-gel is a new method to make TCO for its simplicity, easy doping and large area deposition on the substrates. As-prepared phosphors have intrinsic drawbacks in application, surface coatings have proved an efficient solution against agglomeration of powders, unstable surface electrical and chemical performances.In this thesis, we have investigated the method to obtain transparent and conductive zinc tin oxide films and their application to coat phosphors. The main results are as follow:1. SnO₂:Sb film, ZnO:Al film and alternate multi-layer films of SnO₂-ZnO were obtained respectively, by using sol-gel method. The electrical characterization of the films was basically conducted by conventional four probe technique and current-voltage （I-V） measurements. An phenomenon of deviating from ohmic law based I-V relation has been observed when the multi-layer films were measured at higher temperature. X-ray photoelectron spectroscopy （XPS）, Ultraviolet （UV）-visible spectra and scanning electron microscopy （SEM） have been used to investigated the composition , visible light transmittance and morphology of the samples, respectively.2. It has been found that partially sublimating tin xerogel occurs during oxidization. The matter of tin xerogel sublimating has been deposited on quartz and silicon wafers to form transparent and conductive flms. The experimental conditions were controlled as follow: 0.8g tin xerogel was used as the sublimating source, 5cm from the source to the substrate, oxidizing for 1h under flux pure oxygen （99.9%）. The results of XRD and XPS show that the film has stoichiometry of SnO₂ with tetragonal rutile crystal structure. The average transmittance of the film was above 80% in visible range. SEM and atomic force microscope （AFM） have been used to analyze the morphology of the film. It shows that the nanocrystal is compact and uniform in size and the films is smooth with equal thickness basically. The thickness and resistitvity of the film obtained as above is 70nm from deduction of absorption coefficient and 2.86×10^-2Ω·cm from four-probe measurements.3. Partial sublimation of SnO₂:Sb xerogel during oxidation was utilized to treat the as-prepared ZnS:Mn phosphor. The mass ratio of SnO₂:Sb xerogel to ZnS:Mn phosphors changed from 0.5 to 4.0 and the range of the oxidation temperature was 300-600℃under the given oxygen flux （0.2 L·min-1） and oxidation duration （30 min）.The treated phosphors were characterized by X-ray diffraction （XRD）, photoluminescence （PL）, transmittance electron microscopy （TEM）, and electrical resistance measurements. The results showed that the conductivity of the treated ZnS:Mn phosphors was obviously improved when the mass ratio of SnO₂:Sb xerogel to ZnS:Mn phosphors and the oxidation temperature were 3.0 and 500℃, respectively. The photoluminescence characteristics and crystal structure of the treated ZnS:Mn phosphors remained the same as the as-prepared phosphors.更多还原