稀土元素(La,Y)掺杂GaN的第一性原理计算

First-principles calculation of rareearth element(La,Y)doped GaN

采用基于密度泛函理论的第一性原理赝势平面波方法,对稀土元素La,Y单掺杂和La和Y共掺杂GaN的晶格常数、电子结构及光学性质进行了计算与分析.计算结果表明:掺杂改变了GaN的能带结构,未掺杂和Y掺杂形成导带底和价带顶位于G点的直接带隙半导体,而La掺杂和La和Y共掺杂形成导带底位于G点,价带顶位于Q点的间接带隙半导体.可以通过掺杂元素来调制GaN的禁带宽度和带隙类型,掺杂均提高GaN在低能区的静态介电常数、反射率、折射率,使光子的跃迁强度增大,说明稀土元素La,Y掺杂可有效调制GaN的光电性质.

The lattice constants,electronic structure and optical properties of GaN that single-doped by rare earth elements La,Y and co-doped by La and Y were calculated and analyzed by using the first principle pseudopotential plane wave method based on density functional theory.The results show that the band structure of GaN is changed by doping.the un-doped GaN and doped GaN by Y form direct band gap semiconductor that conduction band bottom and valence band top at same G point,while La single-doped and co-doped by La and Y form indirect band gap semiconductor which conduction band bottom at G point but the valence band top is at Q point.The bandgap width and bandgap type of GaN can be modulated by doping elements,the static dielectric constants,reflectivity and refractive index of GaN in low energy region can be improved and strengthening the transition intensity of photons by doping.Which indicates that the optoelectronic properties of GaN can be effectively modulated by doping rare earth elements La,Y.