Photovoltaic Properties of a-C:N/p-Si Heterojunction Solar Cell Synthesized by Microwave Surface Wave Plasma CVD

Amorphous carbon (a-C) thin films have been synthesized by microwave surface wave plasma chemical vapor deposition at low temperature (<100 degC). The influence of nitrogen doping on the properties a-C films is reported. Argon, acetylene and nitrogen (N) were used as a carrier, source and dopant gases. Analytical methods such as X-ray photoelectron spectroscopy (XPS), Nanopics 2100/NPX200 surface profiler, JASCO V-570 UV/VIS/NIR spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and Solar simulator were employed to investigate chemical, optical, structural and electrical properties of the films. Successfully nitrogen incorporated (29.37 at. %) into the film was found. The optical band gaps decreased from 2.7 to 1.7 eV. The photovoltaic measurements of a-C:N/p-Si structure show that the open-circuit voltage (V_oc) of 4.7 mV and a short-circuit current density (J_sc) of 19.6 muA/cm² under light illumination (AM 1.5 100 mW/cm²). The energy conversion efficiency and fill factor of the solar cell were found to be 2.24times10^-4 % and 0.24 respectively