Cd-S共掺杂ZnO导电性能的第一性原理研究

Study of First Principles of Cd-S Codoping ZnO

在广义梯度近似下,利用密度泛函理论研究了本征Zn O,Cd和S元素单掺杂,Cd-S元素共掺杂ZnO超晶胞体系的结构和电子性质。结果表明:与本征Zn O结构相比,掺杂体系的能带更致密,带间波动更平缓。Cd或S元素的单掺杂减小了带隙的宽度,Cd-S元素共掺杂时,体系中导带距费米能级的位置减小,使体系的带隙减小。当Cd和S的原子比为1:2时,体系的形成能最低,结构更稳定,此时的带隙最小,电子跃迁所需的能量最低,体系的导电性最高。

Under the generalized gradient approximation,the structure and electronic properties of ZnO supercell system with single doping of intrinsic ZnO,Cd and S elements and co-doping of Cd-S elements are studied by using density functional theory.The results show that the energy band of the doping system is denser and the fluctuation between the bands is smoother than that of the intrinsic ZnO structure.The single doping of Cd or S element reduces the width of the band gap.When Cd-S element is codoped,the position of the conduction band from the Fermi energy level in the system decreases,so that the band gap of the system decreases.When the atomic ratio of Cd and S is 1:2,the formation energy of the system is the lowest and the structure is more stable.At this time,the band gap is the lowest,the energy required for electronic transition is the lowest,and the conductivity of the system is the highest.