中文摘要：

MgZnO合金具有可覆盖日盲紫外波段的禁带宽度和晶格匹配的单晶衬底,是理想的日盲紫外探测材料。由于MgO和ZnO分属立方相和六角相,分相问题使高质量单一相MgZnO难以获得。热处理是提高薄膜结晶质量的有效手段。利用MOCVD方法制备了单一立方相Mg0.57Zn0.43O合金薄膜,研究了薄膜的退火行为对薄膜结构和光学性能的影响。研究发现,450℃的原生样品经过550,650,750,850℃氧气氛退火后,薄膜的结晶特性和表面形貌得到明显的改善。随着退火温度的增加,薄膜吸收截止边逐渐蓝移,带隙展宽。X光电子能谱分析发现,随着退火温度增加,Zn含量逐渐减小,这种现象被归结为组分蒸汽压的差异。在退火温度达到950℃时,样品发生了分相,出现了低Mg含量的六角相MgZnO。

英文摘要：

Annealing behavior for cubic-phase Mg0.57Zn0.43O thin films grown at 450 ℃ by metal-organic chemical vapor deposition were studied.After annealed at 550,650,750 and 850 ℃ in oxygen atmospheres,the crystal quality and surface smoothness of the thin films were improved significantly.Their bandgap shifts continuously to the higher energy the increasing annealing temperature.Confirmed by energy dispersive X-ray spectra,the enlarged bandgap was caused by the decrease of Zn content during annealing.Phase separation of the Mg0.57Zn0.43O films with significant surface roughening can also be observed during annealing at 950 ℃.