摘要
基于平面波赝势密度泛函理论,研究了La,Ce,Nd掺杂SnO2的电子结构和光学性质。计算结果表明,La附近的键长变化最大,而Nd附近的键长变化最小,这表明稀土掺杂SnO2引起的晶格畸变与掺杂原子的共价半径大小有关。能带结构表明,稀土掺杂可使SnO2的带隙变窄。La掺杂相比较本征SnO2,带隙减小了0.892 e V,Nd掺杂在SnO2的禁带中引入了3个能级。差分电荷密度分析表明,稀土掺杂使SnO2的电子重新分配且由于f电子的存在使其离子性增强。La原子失电子最多,Nd原子失电子最少,这和计算的能带结果是一致的。光学性质表明,介电函数的虚部和吸收函数因稀土掺杂出现了不同程度的红移,这和计算的能带结果非常吻合。
The lattice parameters, band structures, density of states, electron density differences and optical properties of La, Ce, Nd doped SnO2 are studied by density functional theory （DFT）. The computational results show that the bond length near La are greatest changed, while the change near Nd are least, which indicates the lattice distortion caused by rare earth doped in SnO2 is related to the covalent radius of doping atom. The band structure shows that rare earth doping can make the band gap of SnO2 narrow. The La doping makes the band gap reduced 0.892 eV comparing that of intrinsic SnO2, and Nd doping induces three energy levels in the forbidden band. The electron density difference shows that rare earth doping makes the electron redistribution of SnO2 and the iconicity enhance, especially the existence of f electrons. La atom loses electrons most and Nd atom loses least, which are consistent with the calculated results of band gaps. The calculated results of optical properties show that the imaginary part of the dielectric function and absorption function have a red shift, which agrees well with the calculated results of energy band gap.
出处
《激光与光电子学进展》
CSCD
北大核心
2015年第9期247-254,共8页
Laser & Optoelectronics Progress
基金
陕西省自然科学基础研究计划(2014JM2-5058)
陕西省教育厅科学研究计划(2013JK0917)
延安市科学技术研究发展计划(2013KG-03,2014KG-02)
关键词
材料
SNO2
稀土掺杂
密度泛函理论
电学和光学性质
materials
SnO2
rare earth doping
density functional theotry
electronic and optical property
