Effects of radio frequency powers on the characteristics of a-C:N/p-Si photovoltaic solar cells prepared by plasma enhanced chemical vapor deposition

The effects of radio frequency (rf) powers on the characteristics of a-C:N/p-Si photovoltaic solar cells prepared by plasma enhanced chemical vapor deposition (PECVD) are investigated. As the rf-power raises from 100 to 400 W, the N doping content of a-C:N films increases and the microstructure of a-C:N films is transformed to graphite-like. Alternatively, the short-circuit current and conversion efficiency of a-C:N/p-Si photovoltaic solar cells increase with increasing the rf-power, but the open-circuit voltage and fill factor are less dependent on the rf-power. Although the best performance of a-C:N/p-Si photovoltaic solar cells is achieved with the rf-power of 400 W in this work, it is expected that the performance of a-C:N/p-Si photovoltaic solar cells can be further improved by increasing the rf-power, or adding applied bias and magnetic field on PECVD system.