摘要
利用高真空磁控溅射设备并顺序沉积Cr、Ti和Si层并随后在500℃真空退火6h,在Si（100）衬底上,获得不同Ti掺杂量的CrSi2薄膜。场发射扫描电镜观察表面形貌显示,沉积薄膜具有7~8nm的晶粒且尺寸比较均匀,Ti含量增加,晶粒尺寸略有增加;X射线衍射谱显示沉积薄膜具有单一CrSi2点阵（111）晶面择优取向,在1.16at%到1.74at%的Ti含量范围内,随Ti含量的增加,CrSi2纳米薄膜的（111）择优取向的程度下降,同时,Ti含量增加,薄膜CrSi2点阵常数增加,这表明Ti在CrSi2晶体中以替位形式存在。随着Ti含量增加,沉积薄膜的霍尔系数降低,空穴浓度增加,同时薄膜空穴载流子的迁移率和Seebeck系数单调下降;受空穴浓度增加和迁移率降低的影响,随Ti含量增加,沉积薄膜电导率和功率因子呈现先增加达到最大值后又下降的趋势。
The Ti doped CrSi2 thin films were synthesized on Si（100） substrate by depositing alternatively Cr, Ti and Si layers using multi-target magnetron sputtering system and following annealing 6 h at 500 ℃ in vacuum. The surface morphology from FESEM shows that the grain size of deposited films with relatively uniform size is approximately 7-8 nm and the grain size slightly increases as Ti content in thin films increasing. The deposited thin films possess single （ 111 ） plane preferential orientation of the CrSi2 lattice by XRD pattern. The extent of preferential orientation reduces with increasing Ti content from 1. 16at% to 1. 74at%. It suggests the existence of the substitution of Ti for Cr atom in CrSi2 lattice that the CrSi2 lattice constant increases as the Ti content in thin films increasing. The Hall coefficient, mobility and Scebeck coefficient of the deposited thin films monotonically decreases, but the holes carrier concentration increases as Ti content in thin films increasing. However, the electrical conductivity and power factor of the deposited films firstly increases, reaches a maximum value and decreases with increasing Ti content in thin films due to the results of holes carrier concentration increasing and holes carrier mobility decreasing.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2015年第8期2112-2117,2122,共7页
Journal of Synthetic Crystals
基金
国家自然科学基金(51171118)
