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arXiv 0903.4944cond-mat.mtrl-sci
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(P,N)共掺杂ZnO中p型导电的起源

The origin of p-type conduction in (P, N) co-doped ZnO

Ren-Yu Tian, Yu-Jun Zhao

摘要:

采用第一性原理计算研究了P单掺杂和(P,N)共掺杂ZnO的晶体结构。结果表明,替代型P缺陷在O位形成深受主能级(PO),在Zn位表现为施主能级(PZn),而间隙型P(Pi)则是两性的。在平衡条件下,这些缺陷对ZnO样品的p型导电性贡献很小,因为当EF低于中间带隙(必要的p型条件)时,PZn的形成能远低于Pi或PO的形成能。锌空位(VZn)和PZn-2 VZn复合物被证明是浅受体,其电离能约为100 meV,但它们很容易被PZn缺陷补偿。在富锌条件下,通过适当的磷、氮源选择,PZn-4 NO复合物的形成能可能低于PZn。此外,中性PZn-3 NO被动缺陷可形成正好在ZnO的价带最大值上方的杂质带,如在早期报道的(Ga,N)或(Zr,N)掺杂的ZnO中。这显著降低了PZn-4 NO络合物的受主能级,并有助于改善ZnO中的p型导电性。

英文摘要:

P mono-doped and (P, N) co-doped ZnO are investigated by the first-principles calculations. It is found that substitutive P defect forms a deep acceptor level at O site (PO) and it behaves as a donor at Zn site (PZn), while interstitial P (Pi) is amphoteric. Under equilibrium conditions, these defects contribute little to the p-type conductivity of ZnO samples since the formation energy of PZn is much lower than that of Pi or PO when EF is below mid-gap (a prerequisite p-type condition). Zinc vacancies (VZn) and PZn-2VZn complex are demonstrated to be shallow acceptors with ionization energies around 100 meV, but they are easily compensated by PZn defect. Fortunately, PZn-4NO complexes may have lower formation energy than that of PZn under Zn rich condition by proper choices of P and N sources. In addition, the neutral PZn-3NO passive defects may form an impurity band right above the valence band maximum of ZnO as in earlier reported (Ga,N) or (Zr,N) doped ZnO. This significantly reduces the acceptor level of PZn-4NO complexes, and helps improving the p-type conductivity in ZnO.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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