2DEG Properties of AlScN/GaN and AlYN/GaN HEMTs Determined by Terahertz Optical Hall Effect - Stanishev, Vallery ; 0000-0002-7626-1181; Streicher, I.; Papamichail, Alexis; Rindert, Viktor ; 0000-0001-8143-1088; Paskov, Plamen P.; Leone, S.; Darakchieva, Vanya (Frontiers in Electronic Materials, 2025)