Photoconductivity and AFM study of nitrogen doped a: DLC films

摘要

We present the results of photoconductivity, photosensitivity, and decay time of photocurrentmeasurement as a function of temperature, for both nitrogen doped (N-DLC) and nondoped a:DLCfilms. The a:DLC films were deposited using RF glow discharge of methane gas (CH{sub}4) as asource of carbon. Several films were doped employing nitrogen (N{sub}2) as doping gas. Thespectral response of photosensitvity of doped films shifts to higher energy, similar to the measuredoptical energy gap of these films. Unlike the photosensitivity, the photocurrent of doped film is largerby two orders of magnitude than that of nondoped film. The mobility of doped films (2.43×l0{sup}-5) is also larger by two orders of magnitude than the nondoped films (5.64× l0{sup}-7) atroom temperature. In order to provide nano-scale information about the morphological properties ofthe a:DLC and N-DLC films surface we have used the atomic force microscope.