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arXiv · 1804.00919

Zn vacancy-donor impurity complexes in ZnO

Y. K. Frodason·K. M. Johansen·T. S. Bjørheim·B. G. Svensson·A. Alkauskas
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Abstract

Results from hybrid density functional theory calculations on the thermodynamic stability and optical properties of the Zn vacancy ($V_{\text{Zn}}$) complexed with common donor impurities in ZnO are reported. Complexing $V_{\text{Zn}}$ with donors successively removes its charge-state transition levels in the band gap, starting from the most negative one. Interestingly, the presence of a donor leads only to modest shifts in the positions of the $V_{\text{Zn}}$ charge-state transition levels, the sign and magnitude of which can be interpreted from a polaron energetics model by taking hole-donor repulsion into account. By employing a one-dimensional configuration coordinate model, luminescence lineshapes and positions were calculated. Due to the aforementioned effects, the isolated $V_{\text{Zn}}$ gradually changes from a mainly non-radiative defect with transitions in the infrared region in \textit{n}-type material, to a radiative one with broad emission in the visible range when complexed with shallow donors.

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Y. K. Frodason, K. M. Johansen, T. S. Bjørheim, B. G. Svensson, A. Alkauskas. 2018-04-03. Zn vacancy-donor impurity complexes in ZnO. https://doi.org/10.1103/physrevb.97.104109

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