Polymorphism and Faceting in Ga2O3 Layers Grown by HVPE at Various Gallium‐to‐Oxygen Ratios

In article number 2100331, Sevastian Shapenkov and co‐workers describe phase contents and properties of layers of metastable gallium oxide phases obtained in halide vapor phase epitaxy on different substrates with different oxygen‐to‐gallium ratio. The cover image demonstrates crystallization of gallium oxide on patterned sapphire substrate (upper figures) in secondary electrons and on gallium nitride layer (bottom figures) in cathodoluminescence. On patterned sapphire, α‐Ga2O3 is formed on substrate's cons and κ‐Ga2O3 in valleys. On gallium nitride, there are hexagonal κ‐Ga2O3 pillars correlating with positions of threading dislocations (black dots) in GaN. – This article belongs to the Special Section “Compound Semiconductors”, comprising 14 articles in this issue: see the Guest Editorial (article number 2200031) by Mattias Hammar, Anders Hallén, and Sebastian Lourdudoss.