Photovoltaic Characteristics of Nitrogen Doped Amorphous Carbon Film Grown by Microwave Surface Wave Plasma CVD

Photovoltaic properties of nitrogen doped amorphous carbon (a-C:N) thin films deposited on p-type silicon (ρ-Si) and quartz substrates by microwave (MW) surface-wave plasma (SWP) chemical vapor deposition (CVD) at low temperature (< 100°C) are analyzed in this section. Argon (Ar: 200 sccm), methane (CH4:10 sccm) and nitrogen (N: 5 sccm) were used as carrier, source and doping gases respectively. Analytical methods such as X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy and solar simulator were employed to investigate the chemical, optical and photovoltaic properties of the a-C:N film respectively. The optical gap of the film was found to be 2.3 eV. The photovoltaic measurements under light illumination (AM 1.5, 100 mW/cm
²
) shows that short circuit current density, open circuit voltage, fill factor and photo-conversion efficiency of the film are 0.003 mA/cm
²
, 0.108 V, 0.25 and 1.8×10
^-4
% respectively which suggests the formation of heterojunction between the a-C:N and ρ-Si.