Photoluminescence of Hydrogenated Amorphous Carbon Films

Abstract

Hydrogenated amorphous carbon films have been prepared by the glow-discharge decomposition of ethylene gas. The film shows wide properties depending on gas temperature during discharge. With increasing gas temperature from 200 to 350°C, hydrogen content in the film decreases, and thereby the optical gap decreases from 2.6 to 1.2 eV and the ESR spin density increases from ∼10 17 to ∼10 19 cm -3 . The photoluminescence spectrum consists of two emission bands. The peak energy of the main band shifts from 1.93 to 1.64 eV as the gas temperature increases. Emission intensity is very insensitive to measurement temperature.