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V. I. Nikolaev

Publications and source records attributed to V. I. Nikolaev.

2 recordsLinked to original sources

HVPE growth of corundum-structured $α$-Ga$_2$O$_3$ on sapphire substrates with $α$-Cr$_2$O$_3$ buffer layer

Gallium oxide films were grown by HVPE on (0001) sapphire substrates with and without $α$-Cr$_2$O$_3$ buffer produced by RF magnetron sputtering. Deposition on bare sapphire substrates resulted in a mixture of $α$-Ga$_2$O$_3$ and $ε$-Ga$_2$O$_3$ phases with a dislocation density of about $2\cdot10^{10}$ cm$^{-2}$. The insertion of $α$-Ga$_2$O$_3$ buffer layers resulted in phase-pure $α$-Ga$_2$O$_3$ films and a fourfold reduction of the dislocation density to $5 \cdot 10^9$ cm$^{-2}$.

physics.app-ph

Ion-Beam Modification of Metastable Gallium Oxide Polymorphs

Gallium oxide with a corundum structure (α-Ga2O3) has recently attracted great attention in view of electronic and photonic applications due to its unique properties including a wide band gap exceeding that of the most stable beta phase (\b{eta}-Ga2O3). However, the lower thermal stability of the α-phase at ambient conditions in comparison with the \b{eta}-phase requires careful investigation of its resistance to other external influences such as ion irradiation, ion doping, etc. In this work, the structural changes under the action of Al+ ion irradiation have been investigated for a polymorphic gallium oxide layers grown by hydride vapor phase epitaxy on c-plane sapphire and consisting predominantly of α-phase with inclusions of α(\k{appa})-phase. It is established by the X-ray diffraction technique that inclusions of α(\k{appa})-phase in the irradiated layer undergo the expansion along the normal to the substrate surface, while there is no a noticeable deformation for the α-phase. This speaks in favor of the different radiation tolerance of various Ga2O3 polymorphs, especially the higher radiation tolerance of the α-phase. This fact should be taken into account when utilizing ion implantation to modify gallium oxide properties in terms of development of efficient doping strategies.

cond-mat.mtrl-sci