Synthesis and characterization of Ga2O3 nanosheets on 3C-SiC-on-Si by low pressure chemical vapor deposition

Abstract

This study presents the synthesis of single crystalline β-Ga2O3 nanosheets on SiC by low pressure chemical vapor deposition. High purity gallium (Ga) metal and oxygen as source materials and argon as carrier gas were utilized for the synthesis of the nanosheets on a 3C-SiC-on-Si substrate. These single-crystal Ga2O3 nanosheets are free-standing 2D extrusions from their 1D rods, typically 1.5–7 μm in lateral size and 20–140 nm in thickness, featuring aspect ratios ranging from ∼10 to 350. Structural studies based on transmission electron microscopy and Raman spectroscopy revealed the monoclinic phase of Ga2O3 with a single crystalline nature. High resolution transmission electron microscopy with a selected area electron diffraction pattern recorded on a single β-Ga2O3 nanosheet further confirmed their single crystalline nature, with a growth direction perpendicular to (111) crystallographic plane. The growth process governing the formation of these nanosheets is a vapor-solid growth mechanism since no metal catalyst was used. These β-Ga2O3 nanosheets exhibit new possibilities and potential for future functional nanodevices that would benefit from their extremely large surface area to volume ratios.