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1、第20卷第4期中国有色金属学报2010年4月Vol.20No.4TheChineseJournalofNonferrousMetalsApr.2010文章编号:1004-0609(2010)04-0765-07含空位和杂质缺陷的闪锌矿电子结构的第一性原理计算1212陈建华,曾小钦,陈晔,张辉鹏(1.广西大学资源与冶金学院,南宁530004;2.广西大学化学化工学院,南宁530004)摘要:采用基于密度泛函理论(DFT)的平面波超软赝势方法,研究硫空位、锌空位以及铁和镉杂质对闪锌矿电子结构的影响,分析空位和杂
2、质对闪锌矿的价键结构、能带、态密度、差分电荷密度等的影响。计算结果表明:镉杂质缺陷导致闪锌矿的晶胞参数变大,而硫空位、锌空位和铁杂质均使闪锌矿的晶胞参数变小;硫空位使闪锌矿的带隙变窄,与硫空位相邻的4个锌原子的电荷明显低于其他锌原子的电荷;锌空位使闪锌矿的带隙变宽,费米能级向低能方向偏移,与锌空位相邻的4个硫原子的电荷明显低于其他硫原子的电荷;铁杂质使闪锌矿的带隙变宽,并在带隙中形成一个由铁的3d轨道贡献的杂质能级,费米能级向高能方向偏移;镉杂质对闪锌矿能带结构和态密度的影响较小,在闪锌矿价带−7.5eV处
3、形成一个由镉的4d轨道贡献的能级,Cd—S键布居数下降,共价性减弱。关键词:闪锌矿;空位缺陷;铁杂质;镉杂质;电子结构;第一性原理中图分类号:TD923.13文献标志码:AFirst-principletheorycalculationsofelectronicstructureofsphaleritewithvacancyandimpurity1212CHENJian-hua,ZENGXiao-qin,CHENYe,ZHANGHui-peng(1.CollegeofResourcesandMetallur
4、gy,GuangxiUniversity,Nanning530004,China;2.CollegeofChemistryandChemicalEngineering,GuangxiUniversity,Nanning530004,China)Abstract:TheelectronicstructuresofsphaleritewithZn-vacancy,S-vacancy,Fe-impurityandCd-impuritywerecalculated,respectively,usingtheultr
5、a-softpseudo-potentialapproachoftheplanewavebasedonthedensityfunctionaltheory(DFT),andtheirbondstructure,bandstructure,densityofstatesandthedifferencechargedensitywerestudied.ThecalculatedresultsindicatethattheCd-impuritymakesthelatticeconstantofsphalerite
6、increase,buttheS-vacancy,Zn-vacancyandFe-impuritymakethelatticeconstantdecrease.TheS-vacancymakesthebandgapbecomenarrow,andtheMullikenchargeofZn-atomsaroundtheS-vacancyislowerthanthatofothers.Onthecontrary,theZn-vacancymakesthebandgapbecomewideandtheFermil
7、evelmovestoalowenergylevel,andtheMullikenchargesofS-atomsaroundZn-vacancyarelowerthanthoseofothers.TheFe-impuritymakesthebandgapbecomewideandformsanimpuritylevelinbandgap,whichconsistsofthe3d-electronsoftheFeatom,andtheFermilevelmovestoahighenergylevel.The
8、Cd-impurityhasalittleeffectonthebandstructureanddensityofstatesofsphalerite,andthereisalevelin−7.5eVformedbythe4d-electronoftheCdatom.ThepopulationofCd—Sbonddecreasesandthecovalencebecomesweak.Keywords:sphale