ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The density of electronic defect states in most forms of amorphous carbon deposited at room temperature is found so far to be very high (1018–1022 spins cm−3). In this letter, we demonstrate that the radio-frequency plasma-enhanced chemical vapor deposited hydrogenated amorphous carbon (a-C:H) thin film exhibits the lowest spin density of the order of 1016 cm−3, investigated by using electron spin resonance (ESR) spectroscopy, a very promising reproducible result comparable with high-quality a-Si:H. In addition, the optical gap of a-C:H has been tailored between a wide range, 1.8–3.1 eV. The ESR spectra of all the films reveal a single Lorentzian line whose linewidth ΔHpp varies strongly with the optical gap. Also, there is a strong dependence of spin density on the optical gap, and we show that this dependency is a direct result of structural changes due to sp3/sp2 carbon bonding network. © 2001 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1335548
Permalink