VUV Emission Properties of Rocksalt-structured MgZnO Microcrystals Prepared on Quartz Glass Substrates

Rocksalt-structured (RS) MgZnO crystals are grown on quartz glass substrates by the mist chemical vapor deposition (mist CVD) method. Cathodoluminescence (CL) emission properties are comparatively studied with those for the RS-MgZnO epitaxial film prepared on MgO substrate to explore their potential for vacuum ultraviolet (VUV) emitter. In the experiment, the newly developed VUV spectroscopy system is employed, where the CL and optical transmittance spectra are simultaneously measured. Growths of RS-MgZnO on quartz glass substrate indicate formation of microcrystals (MCs). The MCs dominantly exhibit a near-band-edge VUV emission at 6.20 eV (200 nm) at 6 K and 6.07 eV (204 nm) at 300 K. Moreover, the MCs show a noticeable higher energy shoulder at 6.6 eV (188 nm) at 6 K and 6.4 eV (194 nm) at 300 K. The results ensure potential of RS-MgZnO crystals for active element in VUV emitter regardless of the substrate material.