晶粒尺寸对FeS_2薄膜微应变及光吸收特性的影响  

Effects of Grain Sizes on the Behaviors of Microstrain and Optical Absorption for the FeS_2 Films

作　　者：刘艳辉[1] 汪洋[2] 孟亮 

机构地区：[1]浙江大学材料与化学工程学院,杭州310027 [2]兰州交通大学光电技术与智能控制教育部重点实验室,兰州730070

出　　处：《无机材料学报》2007年第1期143-147,共5页Journal of Inorganic Materials

基　　金：浙江省自然科学基金(Y405016);兰州交通大学光电技术与智能控制教育部重点实验室开放基金(K040117)

摘　　要：采用不同厚度的Fe膜在673K热硫化20h制备出具有不同晶粒尺寸的FeS2薄膜,分析并测定了薄膜组织结构、微应变及光吸收性能．结果表明,Fe膜硫化形成的FeS2薄膜厚度在120-550nm范围内变化时,可导致平均晶粒尺寸在40-80nm之间变化．FeS2晶粒尺寸的变化造成了晶体面缺陷密度的变化,可引起微观内应力水平、缺陷能级分布和晶界势垒高度的变化,进而使得薄膜的微应变、点阵畸变度、光吸收系数及禁带宽度等物理特性随晶粒尺寸的增加而降低．FeS2 thin films with different grain sizes were synthesized by the sulfuration reaction of Fe films with different thickness at 673K for 20h. The microstructure, microstress and optical absorption of the films were investigated. The average grain size of the FeS2 films changes from 40 nm to 80 nm when the film thickness changes from 120nm to 550nm. The internal microstrain, lattice distortion, absorption coefficient and energy gap decrease with the grain size increasing. The mechanism responsible for the result can be attributed to the variation of the degree of microstress, the distribution of energy level of crystal defect states and the height of grain boundary barrier due to the change of the crystal planar defects density with the grain size changing.

关 键 词：FeS2 晶粒尺寸 微应变 禁带宽度 

分 类 号：TN304[电子电信—物理电子学]