天然杂质对闪锌矿电子结构和半导体性质的影响

Effect of Natural Impurities on the Electronic Structures and Semiconducting Properties of Sphalerite

采用密度泛函理论系统研究了分别含有十四种天然杂质的闪锌矿的电子结构,并讨论了这十四种杂质对闪锌矿半导体性质的影响.研究结果表明,锰、铁、钴、镍、铜、镉、汞、银、铅、锑杂质的存在使闪锌矿的带隙变窄,导致吸收带边增大.除了镉和汞杂质外,其余杂质的存在均导致费米能级向高能级方向移动,并且在闪锌矿禁带中产生了杂质能级.铁、镓、锗、铟、锡、锑杂质使闪锌矿的半导体类型由p型变为n型;而锰、钴、镍、铜、镉、汞、银、铅杂质对闪锌矿的半导体类型没有影响.铜杂质使闪锌矿由直接带隙变为间接带隙半导体.

A systematic study of the electronic structures of sphalerite containing fourteen kinds of natural impurities was performed by the density functional theory. The results show that Mn, Fe, Co, Ni, Cu, Cd, Hg, Ag, Pb, and Sb impurities narrow the bandgap of sphalerite and cause the absorption edge to increase. For all impurities except Cd and Hg, the Fermi level shifts to a higher energy level and impurity levels appear in the forbidden band. Fe, Ga, Ge, In, Sn, and Sb impurities change the sphalerite from a p-type to a n-type semiconductor while Mn, Co, Ni, Cu, Cd, Hg, Ag, and Pb impurities have no effect. Cu impurity changes the sphalerite from a direct bandgap to an indirect bandgap type semiconductor.