Fractional-Monolayer 2D-GaN/AlN Structures: Growth Kinetics and UVC-emitter Applications

V. N. Jmerik; D. V. Nechaev; E. A. Evropeitsev; E. M. Roginskii; A. N. Semenov; M. A. Yagovkina; P. A. Alekseev; V. I. Kozlovsky; M. M. Zverev; N. A. Gamov; Tao Wang; Xinqiang Wang; T. V. Shubina; A. A. Toropov

arXiv · 2601.08410

Fractional-Monolayer 2D-GaN/AlN Structures: Growth Kinetics and UVC-emitter Applications

V. N. Jmerik·D. V. Nechaev·E. A. Evropeitsev·E. M. Roginskii·A. N. Semenov·M. A. Yagovkina·P. A. Alekseev·V. I. Kozlovsky·M. M. Zverev·N. A. Gamov·Tao Wang·Xinqiang Wang·T. V. Shubina·A. A. Toropov

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Abstract

The paper reports on fundamental properties of the GaN/AlN quantum wells (QWs) with nominal subcritical thicknesses of 0.75-2 monolayers (MLs). They are grown by plasma-activated molecular beam epitaxy, varying either the nominal thickness or the gallium-to-nitrogen flux ratio. In situ monitoring reveals difference in 2D nucleation and step-flow growth modes of the QWs. The emission charactestics of QWs with integer thicknesses of 1 and 2 MLs depend weakly on the growth mechanism. In contrast, the intensity and spectral position luminescence of QWs with fractional-ML thicknesses are determined by the growth mechanism. Using ab initio calculations, a phenomenological model is proposed that describes fractional-ML QWs either as arrays of 2D quantum disks or as arrays of 2D quantum ribbons, in cases where 2D nucleation or step-flow growth mechanisms predominate, respectively. This model is generally consistent with experimental data on photo- and cathodoluminescence of heterostructures with multiple (250) GaN/AlN QWs. These heterostructures, when pumped by electrom beam at an energy 12.5 keV with a maximum pulse current of 2 A, exhibit linear current dependences of optical peak powers up to 1 and 37 W for wavelengths of 228 and 256 nm, respectively, making them promising for use as powerfull ultraviolet-C emitters.

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V. N. Jmerik, D. V. Nechaev, E. A. Evropeitsev, E. M. Roginskii, A. N. Semenov, M. A. Yagovkina, P. A. Alekseev, V. I. Kozlovsky, M. M. Zverev, N. A. Gamov, Tao Wang, Xinqiang Wang, T. V. Shubina, A. A. Toropov. 2026-01-13. Fractional-Monolayer 2D-GaN/AlN Structures: Growth Kinetics and UVC-emitter Applications. https://arxiv.org/abs/2601.08410

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