Crystal growth and design of Sn-doped β-Ga2O3: Morphology, defect and property studies of cylindrical crystal by EFG

The cylindrical Sn: beta-Ga2O3 crystal with high crystalline quality was successfully designed and grown by the innovative edge-defined film-fed growth (EFG) method equipped with a cylindrical Iridium die. The chal-lenges for the growth of Sn: beta-Ga2O3 crystals were overcome by optimizing the design of an afterheater. The growth morphology of cylindrical beta-Ga2O3 crystal was studied using a theoretical model and the results from experimental crystal growth. The order of importance of growth conditions affecting beta-Ga2O3 crystal growth morphology was examined, based on the morphological features of cylindrical beta-Ga2O3 crystals obtained by the EFG and Czochralski methods. The iridium inclusions with three shapes were observed in bulk beta-Ga2O3 crystal, and the formation mechanism was carefully discussed. The optical bandgap and valence band maximum (VBM) of Sn: beta-Ga2O3 crystal were calculated to be 4.74 eV and 3.49 eV by absorption spectra and X-ray photoelectron spectroscopy (XPS), respectively. The corresponding surface barrier height (Phi(surf)) was 1.25 eV. The carrier concentration of 5.95 x 10(18) cm(-3) was characterized by capacitance-voltage (C-V) measurement. By the Hall measurement, the carrier mobility and resistivity were estimated to be around 51 cm(2) V-1 s(-1) and 3.55 x 10(-2) Omega cm, respectively. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A high-quality crystalline Sn: beta-Ga2O3 crystal was successfully designed and grown using the innovative EFG method, overcoming growth challenges and studying growth morphology factors, optical properties, and carrier characteristics. Inclusions of iridium with three shapes were observed in bulk beta-Ga2O3 crystal, with corresponding surface barrier height, carrier concentration, and mobility values characterized for the crystal.