The Fermi level in diamond
The Fermi level in diamond
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DOI：
10.1088/0953-8984/14/14/307
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发表时间：
2002-04-15
影响因子：
2.7
通讯作者：
Collins, AT
中科院分区：
文献类型：
--
作者：
Collins, AT
金刚石是一种宽带隙材料，具有较大的供体和受体电离能。原则上，在室温或更低的温度下，费米能量被固定在供体或受体水平附近，这取决于哪个在更高的浓度中存在。在具有浅层供体和受体的半导体中，缺陷的平衡电荷态由费米能级的位置决定。然而，在像金刚石这样的绝缘材料中，我们表明费米能级的计算位置并不一定能预测缺陷的正确电荷状态，而是提出电荷状态受到缺陷与供体（或受体）的接近程度的影响。这就定性地解释了电荷态与分离的取代态氮的浓度的依赖关系，也解释了为什么许多光学中心可以在同一颗金刚石中以两种不同的电荷态存在。
Diamond is a wide-band-gap material with large donor and acceptor ionization energies. In principle, at room temperature and below, the Fermi energy is pinned close to the donor or acceptor level, depending on which is present in the higher concentration. In semiconductors with shallow donors and acceptors the equilibrium charge states of defects are determined by the position of the Fermi level. However, in an insulating material like diamond we show that the calculated position of the Fermi level does not necessarily predict the correct charge state of a defect, and propose instead that the charge state is influenced by the proximity of the defect to a donor (or acceptor). Qualitatively this accounts for the dependence of the charge state on the concentration of isolated substitutional nitrogen and also explains why many optical centres can be present in two different charge states in the same diamond.