Nitrogen doping in camphoric carbon films and its application to photovoltaic cell

Carbon films have been deposited on quartz and single-crystal silicon substrates by pulsed laser deposition technique. The soot for the target was obtained from burning camphor, a natural source. The effect of nitrogen (N) incorporation in camphoric carbon film is investigated. Optical gap for the undoped film is about 0.95 eV. The optical gap remains unchanged for low N content and decreases to about 0.7 eV. With higher N content the optical gap increases. The resistivity of the carbon film is increased with N content initially and decreases with higher N content till the film is deposited at 30 mTorr. The results indicate successful doping for the film deposited at low nitrogen content. The J–V characteristics of N-incorporated carbon/silicon photovoltaic cell under illumination are observed to improve upon N-incorporation in carbon layer.