Structure, optical and electrical properties of pulsed laser deposited and ion beam deposited CN_x films

摘要

CN_x films were deposited using pulsed laser deposition (PLD) and ion beam deposition (IBD). The PLD films deposited at substrate temperature T_s = 25 deg C and high N_2 partial pressure have the highest N content (f_N) and polymerike structure, accompanied by large band gap (E_g) and low electrical conductivity ( sigma _(room)). The rise in T_s lowers f_N and induces graphitization of the film structure, so E_g reduces and sigma _(room) increases. IBD (with and without N_2~+ assist) films are graphitic. Higher T_s further enhances the graphitization of the film structure, such that the conduction and valence bands overlap, and sigma _(room) approaches to that of graphite. No evidence was found to show successful formation of the hypothetical beta -C_3N_4 phase in the films.