不同氧压下脉冲激光沉积LiCoO_2薄膜的研究

Study of LiCoO_2 Thin Film Grown under Different Oxygen Pressure by Pulsed Laser Deposition

使用脉冲激光沉积(PLD)法,在不同的氧压下制备了锂离子二次电池正极材料LiCoO2的薄膜。利用X射线衍射(XRD)、原子力显微镜(AFM)等分析测试方法,对沉积的薄膜进行了晶体结构和表面形貌的分析。结果显示,氧压达到正常标准时(20 Pa),LiCoO2薄膜具有明显的c轴择优取向,同时薄膜的晶粒尺寸更为均匀,表面更为光滑。而氧压较低(1 Pa)时,薄膜表现为随机取向。这些结果表明,PLD方法制备LiCoO2薄膜时应该充分考虑腔体气压对等离子体的散射作用以提高薄膜表面的质量。

LiCoO2 thin film samples have been prepared by pulsed laser deposition（PLD） under different oxygen pressure. The crystal structure and surface morphology of the samples were analysed by the technique of X-ray diffraction （XRD） and atomic force microscopy （AFM）. When the oxygen pressure reach the normal standard（20Pa）, the LiCoO2 thin films display the c-axis orientation, and show the more uniform grain size and smoother surface than the samples of 1 Pa. The thin films prepared under the low oxygen pressure （ 1 Pa） exhibit the random orientation. These results suggest, when using PLD method to prepare LiCoO2 thin films, the cavity pressure on plasma scattering should be fully considered in order to improve the quality of the surface morphology of the thin films.