硫化过程中FeS_2薄膜组织结构和电学性能的变化

Evolution of microstructure and electrical properties of FeS_2 thin films in sulfuration processes

采用Fe膜热硫化法在673K和773K温度下形成了FeS2多晶薄膜.分析了不同硫化时间对晶体结构、化学成分、晶粒大小、电阻率和载流子浓度的影响.673K下硫化超过20h及773K温度下硫化超过1h,Fe膜生成FeS2比较充分.随硫化时间延长,673K下硫化的薄膜晶粒直径基本保持在50nm左右,但电阻率增大,载流子浓度下降.773K下硫化的薄膜晶粒尺寸及电阻率均随硫化时间延长而明显增大,但载流子浓度变化不明显,通常低于1×1025m-3的水平.

Polycrystalline FeS2 thin films were prepared by thermally sulfurating iron layers at 673 K and 773 K for different length of time. Their crystal structure, chemical composition, grain size, electrical resistivity and carrier concentration were investigated. Thermal sulfuration at 673 K for more than 20 h or at 773 K for more than 1 h could completely transform Fe layers into FeS2 thin films. With prolonging sulfuration time at 673 K, the films showed a nearly constant grain diameter of about 50 nm but evident increase in electrical resistivity and general decrease in carrier concentration. The films sulfurated at 773 K increased faster in grain diameter and electrical resistivity but not in carrier concentration level is generally lower than 1×1025 m-3.