Optical characterstics of carbon based semiconductors

Abstract

The photoluminescence (PL) in a-C:H:N was measured using a 2.4leV Ar ion laser line for varying N content. The PL results show a lowering of the PL peak energy and a spectral line width broadening as the N content in the film increases. Decomposition of the PL spectra into a series of Gaussian sub-peak levels shows two distinct peaks at 2.2 and 2.1eV and a broad peak at 1.7eV. It is found that the apparent lowering in the PL peak energy and the spectral line width broadening with increasing N content can be understood in terms of an increase in intensity of the sub-peak at 2.1eV with respect to that at the higher energy (2.2eV). The 1.7eV, 2.1eV and 2.2eV sub-peaks are also found in a-C:H without N.