脉冲激光沉积制备MgxNi1-xO合金薄膜的表征及光学性质研究

摘要

应用脉冲激光沉积(PLD)技术,固定脉冲激光能量密度为5 J/cm2,调节薄膜生长基底温度为300～700℃,制备了系列MgxNi1-xO合金薄膜.通过透射电子显微镜(TEM)、X射线光电子能谱(XPS)、原子力显微术(AFM)等表征分析手段,详细分析了薄膜的成分及组织,研究了退火处理对样品的影响.通过UV-Vis分光光度计研究了透射光谱,结合理论计算了光学带隙宽度.结果表明:薄膜由非晶及多晶构成,紫外吸收边约为290 nm,接近日盲波段的上限;衬底温度为500℃、激光脉冲能量密度为5 J/cm2时生长的薄膜在短波部分吸收强烈,而长波部分几乎不吸收,有利于紫外探测;退火处理改善了样品表面质量,但不能有效拓宽光学带隙.%A series of Mgx Ni1-x O alloy films were prepared by pulsed laser deposition.In the procedure,the laser energy density was fixed at 5 J/cm2 ,while the temperature of heated substrate varied from 300 ℃ to 700 ℃.The composition and micro-structure of the as deposited films were characterized by atomic force microscopy (AFM),transmission electron microscopy (TEM)and X-ray photoelectron spectroscopy(XPS).The influence of annealing on the sample was also studied.UV-VIS spec-trophotometer was used to analyse the transmittance of the films.Some interesting results were obtained.The as deposited Mgx Ni1-x O film was found constituted by crystalline component and amorphous one.The ultraviolet absorption edge were located at about 290 nm,near the superior limit of solar-blind wavelength.It is also found that the film prepared at 5 J/cm2-500 ℃ have strong absorption within short wave range,but scarce absorption in infrared and visible wave band,which is useful to ultraviolet detection.The annealing treatment was very effective to improve the surface quality of the film,but had little effect on the optical band gap.