铝掺杂氧化锌薄膜在玻璃衬底上的RF反应共溅射低温织构生长

Preparation and Characterization of Al Doped ZnO Thin Films Textured on Glass at Low Temperature by RF Reactive Co-Sputtering

以金属锌 ( Zn)和铝 ( Al)为靶材采用射频 ( RF)反应共溅射技术在低温 ( 2 0 0℃ )玻璃衬底上沉积了铝掺杂氧化锌 ( Zn O∶ Al)薄膜 .运用扫描电子显微镜 ( SEM)、能量色散 X射线谱 ( EDX)、表面轮廓仪 (α- Step)、X射线衍射( XRD)和双光束紫外 -可见光谱仪 ( U V- VIS)等分别对沉积样品的表面和断面的形貌结构、组成成分和光学特性进行了分析表征 .研究了反应气体氧与氩流量比 ( O2 / Ar)和 RF溅射功率对沉积样品的生长速率、结构特征和光电学性质的影响 .结果表明 ,薄膜的成长速率强烈依赖于 RF溅射功率 ,而薄膜的结构形貌和成分的化学配比则主要由反应气体流量比 O2 / Ar决定 .通过对沉积参数的优化但未经退火处理 ,得到了六角纤锌矿结构单一 ( 0 0 0 2 )结晶方向的 Zn O∶ Al薄膜 ,其可见光透过率达 85 % ,电阻率在 10 - 1 ～ 10 3Ω· cm之间 .实验发展的低温 RF共溅射技术不仅具有造价低廉、工艺简单可靠和材料来源广泛等特点 ,而且还能有效防止器件底层材料间的互扩散 ,沉积薄膜的性能基本符合光电器件涂层特别是薄膜太阳电池窗口层应用的要求 。

Al doped zinc-rich ZnO thin films are prepared at low temperature (200℃) using RF reactive co-sputtering technique with metal zinc and aluminum as target and soda lime glass as substrates.The morphology and microstructure,compositions and optical properties of the deposited films are characterized by employing SEM,EDX,α-step,XRD,and UV-VIS methods.The influences of O 2/Ar ratio in the reactive gases and RF power on growth rate,structure,and optical properties are investigated.The results show that growth rate of the deposited films is mainly determined by RF power while stoichiometry of the composition and the structures have strong dependence on O 2/Ar ratio in the reactive gases.By optimizing the processing parameters,strong textured single crystalline ZnO films with the orientation of (0002),a transmittance of over 85% and a resistivity of 10 -1～10 3Ω·cm are obtained without post treatment of annealing.These properties can well meet the requirements for the applications of ZnO film,especially as the window layers of Cu-Ⅲ-Ⅳ 2 thin film solar cells.