Keiko Ikoma

Blue Electroluminescence of Thin-Film Diamond Made by the Hot-Filament Method

Blue electroluminescence has been observed in thin-film diamond deposited on a substrate when a mixture of methane and hydrogen gases react under heat treatment by tungsten filament. The diamond active layer is sandwiched between metal oxide insulating layers (HfO2 and Al2O3) which are formed by evaporation of metal oxides in oxygen plasma. Indium tin oxide film is used as a transparent electrode. The electroluminescence spectrum shows the peak at 435 nm and luminance is 3.6 cd/m2 at an applied voltage of 400 V.

Raman Scattering Spectroscopy of 3C-SiC(111) Heteroepitaxial Films

Raman scattering spectra of 3C-SiC films, grown heteroepitaxially on Si(111) substrates by chemical vapor deposition (CVD), were measured to obtain information on the relaxation mechanism of the internal stress of the 3C-SiC films. The internal stress is found to be relaxed by the formation of the voids at the interface between 3C-SiC film and Si substrate during the CVD process.