Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 27: Zinc Oxide and Zinc Selenide

HL 27.5: Vortrag

Dienstag, 8. März 2016, 10:30–10:45, H17

Mechanisms for p-type conduction in ZnO, (Zn,Mg)O, and related oxide semiconductors — •Daniel F. Urban, Wolfgang Körner, and Christian Elsässer — Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstr. 11, 79108 Freiburg, Germany

Intrinsically n-type oxide semiconductors like ZnO and (Zn,Mg)O can be turned into p-type materials if a sufficient amount of shallow acceptor defect levels in the band gap is created and a depletion of the net electron concentration which activates the acceptor levels is achieved. Motivated by recent experiments [1,2] on (Zn,Mg)O doped with nitrogen we analyze the defect levels of substitutional nitrogen (N_O), zinc vacancies (v_Zn) and their combination by means of self-interaction-corrected density functional theory calculations. We show how the interplay of defects can lead to the favoured shallow acceptor defect levels, although the levels of isolated point defects N_O lie too deep in the band gap for being responsible for p-conduction. We relate our results to p-type channels seen in polycrystalline ZnO containing grain boundaries [3] which allows us to develop an understanding of p-type mechanisms in ZnO, (Zn,Mg)O, and related materials.

[1] L. Liu, J. Xu, et al, Phys. Rev. Lett. 108, 215501 (2012).

[2] M. N. Amini, et al, Phys. Chem. 17, 5485 (2015).

[3] W. Körner and C. Elsässer, Phys. Rev. B 81, 085324 (2010).