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arXiv · 2310.18094

Deep-level structure of the spin-active recombination center in dilute nitrides

A. C. Ulibarri·C. T. K. Lew·S. Q. Lim·J. C. McCallum·B. C. Johnson·J. C. Harmand·J. Peretti·A. C. H. Rowe
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Abstract

A Gallium interstitial defect (Ga$_{\textrm{i}}$) is thought to be responsible for the spectacular spin-dependent recombination (SDR) in GaAs$_{1-x}$N$_x$ dilute nitride semiconductors. Current understanding associates this defect with two in-gap levels corresponding to the (+/0) and (++/+) charge-state transitions. Using a spin-sensitive photo-induced current transient spectroscopy, the in-gap electronic structure of a $x$ = 0.021 alloy is revealed. The (+/0) state lies $\approx$ 0.27 eV below the conduction band edge, and an anomalous, negative activation energy reveals the presence of not one but \textit{two} other states in the gap. The observations are consistent with a (++/+) state $\approx$ 0.19 eV above the valence band edge, and a hitherto ignored, (+++/++) state $\approx$ 25 meV above the valence band edge. These observations can inform efforts to better model the SDR and the Ga$_{\textrm{i}}$ defect's local chemical environment.

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A. C. Ulibarri, C. T. K. Lew, S. Q. Lim, J. C. McCallum, B. C. Johnson, J. C. Harmand, J. Peretti, A. C. H. Rowe. 2023-10-27. Deep-level structure of the spin-active recombination center in dilute nitrides. https://doi.org/10.1103/physrevlett.132.186402

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