Solid‐Solution Limits and Thorough Characterization of Bulk β‐(AlxGa1‐x)2O Single Crystals Grown by the Czochralski Method

• DOI: 10.1002/admi.202400122
• Publication Date: 2024-06-14T10:33:49Z
• Authors: Zbigniew Galazka; Andreas Fiedler; Andreas Popp; Palvan Seyidov; Saud Bin Anooz; Roberts Blukis; Jana Rehm; Kornelius Tetzner; Mike Pietsch; Andrea Dittmar; Steffen Ganschow; Arub Akhtar; Thilo Remmele; Martin Albrecht; Tobias Schulz; Ta‐Shun Chou; Albert Kwasniewski; Manuela Suendermann; Thomas Schroeder; Matthias Bickermann
• Keywords: Monoclinic crystal system; Lattice constant; Crystal (programming language)

Abstract With comprehensive crystal growth experiments of β‐(Al x Ga 1‐x ) 2 O 3 by the Czochralski method this work concludes a maximum [Al] = 40 mol% (35 in melt) that can be incorporated into β‐Ga lattice while keeping single crystalline and monoclinic phase, resulting formula 0.4 0.6 . Transmission Electron Microscopy (TEM) analysis reveals random distribution Al across both octahedral tetrahedral sites. This has shown, incorporation only [Ga] ≥ 5 α‐Al crystals leads to phase separation (α + θ)‐Al electrical measurements proves an increase resistivity :Mg as compared :Mg. The static dielectric constant refractive index decrease with [Al]. Raman spectra shows continuous shift broadening peaks, low energy optical phonons A g (3) having large contribution electron mobility. Further, Ir decreases [Al], wherein 4+ peak disappears already at 15 mol%. Finally, thermal conductivity on show drastic its values about 1/3 value 30