制备工艺对Zn1-xMgxO薄膜结构及光学性能的影响

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Zn_1-xMg_xO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Zn_1-xMg_xO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, Zn_{关键词： 1-x}Mg_xO薄膜')" href="#">Zn_1-xMg_xO薄膜 制备工艺 结构 光学性质

Influence of fabrication technique on structure and photoluminescence of Zn1-xMgxO thin films

Single-crystalline Zn_1-xMg_xO 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 Zn_1-xMg_xO 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 Zn_1-xMg_xO 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 Zn_0.75Mg_0.25O 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 （O_Zn） and interstitial oxygen vacancies （O_i）, and the ultraviolet emission peak has a blue shift due to annealing.