Band gap variation in copper nitride thin films

Copper nitride thin films have been prepared by pulsed direct current reactive magnetron sputtering. Structural, morphological and optical properties of the as-deposited films have been studied. X-ray diffraction analysis shows that the films are polycrystalline single phase of Cu₃N. Prominent growth along (100) plane is observed for higher nitrogen flow rate whereas growth along (111) plane is observed for relatively lower nitrogen flow rate. The band gap of this material changes from 1.02 to 1.40 eV by varying the nitrogen flow rate and deposition time.