(1. 廣西大學(xué) 資源與冶金學(xué)院，南寧 530004；2. 廣西大學(xué) 化學(xué)化工學(xué)院，南寧 530004)
摘 要: 采用基于密度泛函理論(DFT)的平面波超軟贗勢(shì)方法，研究硫空位、鋅空位以及鐵和鎘雜質(zhì)對(duì)閃鋅礦電子結(jié)構(gòu)的影響，分析空位和雜質(zhì)對(duì)閃鋅礦的價(jià)鍵結(jié)構(gòu)、能帶、態(tài)密度、差分電荷密度等的影響。計(jì)算結(jié)果表明：鎘雜質(zhì)缺陷導(dǎo)致閃鋅礦的晶胞參數(shù)變大，而硫空位、鋅空位和鐵雜質(zhì)均使閃鋅礦的晶胞參數(shù)變小；硫空位使閃鋅礦的帶隙變窄，與硫空位相鄰的4個(gè)鋅原子的電荷明顯低于其他鋅原子的電荷；鋅空位使閃鋅礦的帶隙變寬，費(fèi)米能級(jí)向低能方向偏移，與鋅空位相鄰的4個(gè)硫原子的電荷明顯低于其他硫原子的電荷；鐵雜質(zhì)使閃鋅礦的帶隙變寬，并在帶隙中形成一個(gè)由鐵的3d軌道貢獻(xiàn)的雜質(zhì)能級(jí)，費(fèi)米能級(jí)向高能方向偏移；鎘雜質(zhì)對(duì)閃鋅礦能帶結(jié)構(gòu)和態(tài)密度的影響較小，在閃鋅礦價(jià)帶−7.5 eV處形成一個(gè)由鎘的4d軌道貢獻(xiàn)的能級(jí)，Cd—S鍵布居數(shù)下降，共價(jià)性減弱。
關(guān)鍵字: 閃鋅礦；空位缺陷；鐵雜質(zhì)；鎘雜質(zhì)；電子結(jié)構(gòu)；第一性原理
sphalerite with vacancy and impurity
（1. College of Resources and Metallurgy, Guangxi University, Nanning 530004, China;
2. College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China）
Abstract:The electronic structures of sphalerite with Zn-vacancy, S-vacancy, Fe-impurity and Cd-impurity were calculated, respectively, using the ultra-soft pseudo-potential approach of the plane wave based on the density functional theory(DFT), and their bond structure, band structure, density of states and the difference charge density were studied. The calculated results indicate that the Cd-impurity makes the lattice constant of sphalerite increase, but the S-vacancy, Zn-vacancy and Fe-impurity make the lattice constant decrease. The S-vacancy makes the band gap become narrow, and the Mulliken charge of Zn-atoms around the S-vacancy is lower than that of others. On the contrary, the Zn-vacancy makes the band gap become wide and the Fermi level moves to a low energy level, and the Mulliken charges of S-atoms around Zn-vacancy are lower than those of others. The Fe-impurity makes the band gap become wide and forms an impurity level in band gap，which consists of the 3d-electrons of the Fe atom, and the Fermi level moves to a high energy level. The Cd-impurity has a little effect on the band structure and density of states of sphalerite, and there is a level in −7.5 eV formed by the 4d-electron of the Cd atom. The population of Cd—S bond decreases and the covalence becomes weak.
Key words: sphalerite; vacancy defect; iron-impurity; cadmium-impurity; electronic structure; first principle theory
