热氧化法与PLD方法制备ZnO薄膜的特性比较

The Comparison of the Properties of ZnO Thin Films Fabricated by Thermal Oxidation and PLD

用热氧化与脉冲激光沉积(PLD)两种方法在Si(111)上制备了ZnO薄膜。对两种方法制备的薄膜的形貌、结构和室温下的荧光光谱作了比较,并对ZnO薄膜紫外光(UV)的发射机理作了初步的分析,发现与PLD方法相比,热氧化法制备的ZnO薄膜所产生的紫外光发射强度(17816任意相对强度单位a.u.)、半高宽(10nm)和紫外光与可见光的强度比(大约200∶1),都非常优异,认为热氧化法制备的ZnO薄膜的树枝状微晶界面及其方向的随机性有利于紫外光的发射和观测,而PLD方法制备的ZnO薄膜是垂直于衬底的六角柱状结构,紫外光最强的方向在垂直于侧面的方向上。

ZnO thin films were prepared by thermal oxidation and pulsed laser deposition. The morphologies, structures and photoluminescence spectra of the ZnO films were investigated and compared and the mechanics of the UV emission of ZnO thin films were preliminary studied. Compared with PLD method, the ZnO films fabricated by thermal oxidation have stronger UV emission,narrower FWHM of UV peaks and larger ratio of the intensity of UV peaks to visible emission. The reason for it is that the ZnO films fabricated by thermal oxidation have random distribution dendritic microcrystal structure and this is very benefit for UV emission and subsequent measurement. However,the PLD ZnO films have hexangular column structure with high orientation perpendicular to the substrates,and the strongest UV emissions exist in the direction vertical to the lateral surface.