脉冲激光沉积法(PLD)生长Co掺杂ZnO薄膜及其磁学性能  

Fabrication and Magnetic Properties of Co-doped ZnO Thin Films by Pulsed Laser Deposition

作　　者：叶志高[1] 朱丽萍[1] 彭英姿[2] 叶志镇[1] 何海平[1] 赵炳辉[1] 

机构地区：[1]浙江大学硅材料国家重点实验室,浙江杭州310027 [2]杭州电子科技大学理学院材料物理研究所,浙江杭州310018

出　　处：《发光学报》2008年第3期486-490,共5页Chinese Journal of Luminescence

基　　金：国家“973”计划(2006CB604906);国家自然科学基金(50532060,50772099)资助项目

摘　　要：采用脉冲激光沉积(PLD)法在单晶Si(100)及石英衬底上生长Co掺杂ZnO薄膜,并且比较了不同生长条件下薄膜的性能。实验观察到了700℃、0.02Pa氧压气氛下生长的Co掺杂ZnO薄膜显示室温磁滞回线。采用XRD、SEM等手段对Co掺杂ZnO薄膜的晶体结构及微观形貌进行了分析,得到的ZnO薄膜具有高度的c轴择优取向,结构比较致密,表面平整度较高,并且没有发现Co的相关分相,初步表明Co有效地掺入了ZnO的晶格当中。霍尔测试表明Co掺杂ZnO薄膜样品保持了半导体的电学性能,电阻率为0.04Ω·cm左右,载流子浓度约为1018/cm3,迁移率都在18.7cm2/V·s以上。实验结果表明材料保持了ZnO半导体的性能,并具有室温铁磁性。Diluted magnetic semiconductors （ DMS）, in which some atoms of host semiconductors are randomly substituted by magnetic atoms, are regarded as key materials for spintronics because they have charge and spin degrees devices since its of freedom in a single substance. ZnO is a potential candidate for applications of spintronics possibility for room temperature ferromagnetism and its intrinsic excellent electrical properties. ZnO is also suitable for fabricating cartier controllable ferromagnetism because carrier-controlling techniques for ZnO have been well established. And among the methods used for deposition of thin films, PLD is effective and has the advantage that the ratios of the elemental components of the bulk and film are almost the same, even for chemically complex systems. In this paper, Zn0.95 Co0.05 O thin films were prepared by pulse laser deposition（PLD） on silicon（100） and quartz substrates. By optimizing the growth conditions, the Codoped ZnO thin films obtained at temperature of 700℃ and oxygen pressure of 0.02 Pa showed magnetism even at room temperature. The X-ray diffraction patterns suggested that the obtained films showed c axis orientation preference, and Co related phases such as Co2O3 didn＇t appear, simply indicating that Co ions had been successfully doped into ZnO crystal lattices. SEM images showed that the films have dense surfaces with small roughness. The obtained sample was measured to have a hole concentration of -10^18 cm^-3, a mobility of 18.7cm^2·V^-1·s^-1,and a resistivity of about 0.04Ω·cm, maintaining semieonduetivity. And the magnetization of the Co-doped ZnO film can be measured at 12K, even at room temperature.

关 键 词：氧化锌 磁性 CO掺杂 脉冲激光沉积 

分 类 号：O472.5[理学—半导体物理]