n型透明导电薄膜CdIn_2O_4电学性质的研究和大面积制备的最佳条件  

Study on electrical properties of n-type transparent and conductive CdIn_2O_4 thin film and the optimum preparation parameters for large-area film

作　　者：伞海生[1] 陈冲[1] 何毓阳[1] 王君[1] 冯博学[1] 

机构地区：[1]兰州大学磁学与磁性材料教育部重点实验室,兰州730000

出　　处：《物理学报》2005年第4期1736-1741,共6页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :698760 18);国家高技术研究发展计划 (批准号 :2 0 0 1AA3 12 190 )资助的课题~~

摘　　要：在Ar +O2 气氛中 ,采用射频反应溅射Cd In靶制备CdIn2 O4 薄膜 .制得的薄膜经x射线衍射 (XRD)检测为CdIn2 O4 和CdO相组成的多晶 .从理论上分析了热处理前后氧空位、掺杂点缺陷和富氧电子陷阱在影响膜的载流子浓度和电子散射中所起的重要作用 .同时 ,对样品进行Hall效应、Seebeck效应测试并得出不同载流子浓度下的迁移率、有效质量、弛豫时间以及它们之间的相互关系 ,特别强调了弛豫时间的重要性 .为了提高导电膜的透射率 ,还分析了Burstein Moss漂移和带隙收缩对光带隙的影响 ,并在薄膜制备时选择了合适的衬底温度Ts≈ 2 80℃ .实验表明 ,在氧分压为 8%左右时制备的薄膜质量较好 ,热处理后的指标大约为迁移率 μH =31× 10 - 4m2 V·s ,电阻率 ρ =1 89× 10 - 5Ω·m .Transparent and conductive oxides CdIn2O4 thin films were prepared by radio-frequency reactive sputtering from a Cd-In alloy target in Ar + O2 atmosphere. The structure and constitution of the films were obtained by x-ray diffraction. All films prepared contained the polycrystalline CdIn2O4 while a secondary crystalline phase of CdO was also present. Theoretically, it is proposed that three types of point defects play the most important role in affecting the carrier concentration and the scattering of conduction electrons, namely, oxygen vacancies, impure point defects and dissolved surplus oxygen trap centers. By the measurement and computing for Hall and themopower, we could get carrier concentration, Hall mobility, effective mass and relaxation time. At the same time, this paper formulated the effect on optical band-gap due to band-gap narrowing and Burstein-Moss (B-M) shift, and a proper substrate temperature, namely Ts approximately equals 280°C, was used in sputtering for getting higher transmittance of light. Analysis indicated that better thin films were prepared at oxygen density of 8%. By post-deposition heat treatment, a charge-carrier mobility of 31 × 10-4m2/V·s and resistivity of 1.89 × 10-5 Ω·m were obtained, and the thin films also retain high visible transmittance.

关 键 词：透明导电薄膜 射频反应溅射 CdIn2O4 电学性质 导电机制 带隙收缩 

分 类 号：O484.4[理学—固体物理]