Structure and luminescence properties of an amorphous hydrogenated carbon

Publisher Website
Google Scholar
Abstract
A low hydrogen content form of amorphous hydrogenated carbon (a-C:H) was deposited from a magnetically confined plasma, for a range of self bias voltages. The structure was characterized in terms of its density, sp(3) bonding fraction, H content, and H bonding. The Tauc optical gap was found to vary from 2 to 3 eV as the negative bias voltage decreased. The density of paramagnetic centres ranged from below 10(18) cm(-3) to above 10(20) cm(-3). The films are strongly photoluminescent (PL) at room temperature. Their PL properties were measured and correlated with the optical gap and defect density. The PL and the PL efficiency was found to increase strongly with optical gap.