制备工艺对Zn1-xMgxO薄膜结构及光学性能的影响  

Influence of fabrication technique on structure and photoluminescence of Zn_(1-x)Mg_xO thin films

作　　者：王伟娜[1] 方庆清[1] 周军[1] 王胜男[1] 闫方亮[1] 刘艳美[1] 李雁[1] 吕庆荣[1] 

机构地区：[1]安徽大学物理与材料科学学院 光电信息获取与控制教育部重点实验室,合肥230039

出　　处：《物理学报》2009年第5期3461-3467,共7页Acta Physica Sinica

摘　　要：采用脉冲激光沉积(PLD)方法在单晶Si(100)衬底上沿c轴方向生长单晶Zn1-xMgxO薄膜,通过X射线衍射(XRD)、原子力显微镜(AFM)、扫描电镜(SEM)和荧光光谱(PL)研究了膜厚、Mg含量、退火温度及氧气氛等制备工艺对Zn1-xMgxO薄膜的结构、形貌和光学性质的影响.实验结果表明,Mg含量x≤0.15时,Zn1-xMgxO保持六角纤锌矿结构,0.25≤x≤0.35时为立方结构,经过600℃退火之后,Zn0.75Mg0.25O转化为六角纤锌矿结构;后续退火有利于晶粒长大,一定的氧气氛也有利于减少晶体缺陷和薄膜的c轴应力,但是过量的氧气容易与Mg元素结合形成MgO,不利于ZnO六角纤锌矿结构的生长.对Zn0.925Mg0.075O薄膜进行荧光光谱分析,分析结果表明缺陷发光峰主要与锌空位、锌位氧(OZn)或氧间隙(Oi)等缺陷有关,退火可以使紫外发射峰蓝移.Single-crystalline Zn1- x Mgx O thin films with c-axis orientation have been deposited on Si（100） substrate by pulsed lser deposition. The effect of the thickness, Mg content, annealing temperature and oxygen atmosphere on the structure, morphology and photoluminescence of the Zn1- x Mgx O thin films are studied by X-ray diffraction, atomic force microscopy, scanning electron microscopy and photoluminescence spectra. The results indicate that the hexagonal wurtzite type of Zn1-x Mgx O can be stabilized up to Mg content x 〈 0. 15, and the cubic type can be observed when 0.25 ≤ x≤0.35. The grain size of the samples increased by the post-annealing, and the structure of the Zn0.75 Mg0.25 O film changed from cubic to hexagonal wurtzite type when annealed at 600 ℃. An appropriate oxygen pressure can reduce both the number of defects and the c-axis stress. But superfluous oxygen is apt to combine with Mg and hinders the growth of hexagonal wurtzite type ZnO. Photoluminescence spectrum indicates that the defect-level peak is mainly related with the zinc vacancy, substitutional O on the zinc site （OZn） and interstitial oxygen vacancies （Oi）, and the ultraviolet emission peak has a blue shift due to annealing.

关 键 词：Zn1-xMgxO薄膜 制备工艺 结构 光学性质 

分 类 号：O484[理学—固体物理]