Study of iron-catalysed growth ofβ-Ga2O3nanowires and their detailed characterization using TEM, Raman and cathodoluminescence techniques

In this paper, we demonstrate a new catalyst (Fe) to grow single crystalline beta-gallium oxide ( β -Ga 2 O 3 ) nanowires (NWs) via the vapour–liquid–solid mechanism using the chemical vapour deposition technique. The structural studies of these NWs showed the highly crystalline monoclinic phase of Ga 2 O 3 . This was confirmed by detailed scanning transmission electron microscope investigations demonstrating the NW to be single crystalline β -Ga 2 O 3 , growing along the normal of the plane. We also compared Raman and cathodoluminescence (CL) properties of the as-grown β -Ga 2 O 3 NWs with a bulk Ga 2 O 3 single crystal grown by the Czochralski method. It was observed that Raman peak positions of a single β -Ga 2 O 3 NW had a red frequency shift of about 0.3–1.4 cm −1 as compared to a bulk Ga 2 O 3 single crystal, which was in fact quite small. In addition, the CL measurements of β -Ga 2 O 3 NWs and the bulk Ga 2 O 3 single crystal exhibited similar spectra, having a strong broad UV–blue emission band and a weak red emission band. Moreover, the structural, morphological and optical properties of Fe-catalysed β -Ga 2 O 3 NWs were comparable to those of Au-catalysed β -Ga 2 O 3 NWs.