利用反应脉冲激光沉积法,以金属钴为靶材,通过改变衬底温度、反应气体氧气的流量等工艺参数,先后在玻璃衬底上成功制备了CoO薄膜以及Co3O4薄膜。通过X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见光吸收光谱(UV-Vis)研究了沉积工艺参数对沉积薄膜的晶体结构和光学特性的影响。结果表明,当氧气流量小于15sccm时,沉积的薄膜为岩盐矿结构的CoO,而当氧气流量大于15sccm时,沉积的薄膜为尖晶石矿结构的Co3O4。通过对紫外-可见吸收光谱的数据分析,证明CoO和Co3O4薄膜均为间接能带结构,禁带宽度分别为0.82eV和1.21eV。
CoO and Co3O4 thin films have been deposited on glass substrates at different temperatures and with various oxygen flow rates by reactive pulsed laser deposition(PLD) techniques.High purity metallic Co disk was used as the target material,and high purity oxygen was used as the reactive gas.X-ray diffractometry(XRD),X-ray photoelectron spectroscopy(XPS),and UV-visible spectrometry were applied to characterize the crystalline phases of the deposited films.Results show that when the oxygen flow rate is less than 15sccm,the deposited films are rock salt type CoO,while films deposited at an oxygen flow rate greater than 15sccm,the deposited films are spinel type Co3O4.The indirect band structures of both the CoO and Co3O4 phases are proved by UV-Vis absorbance spectra,with bandgaps of 0.82eV for CoO and 1.21eV for Co3O4,respectively.