Physical and Microstructural Properties of Radio-Frequency Plasma-Enhanced Chemical Vapor Deposition Grown n-Type Phosphorus Doped Amorphous Carbon Films on the Contribution to Carbon-Based Solar Cells

Abstract

The physical and microstructural properties of phosphorus doped n-type amorphous carbon (n-C:P) films grown from a radio-frequency (rf) discharge in methane gas as a function of rf power (Prf) was previously determined, and their influence on the electronic properties is now analyzed. It is shown that Prf plays a major role in the deposition of n-C:P films. The Raman scattering, Fourier transform infrared spectroscopy (FTIR), optical spectroscopy, Electron spin resonance (ESR) analyses and electrical resistivity measurement have confirmed successfull phosphorus doping. Moreover, the fabricated n-C:P on p-type silicon substrates (n-C:P/p-Si) heterojunction solar cells, when exposed to AM 1.5 illumination (100 mW/cm2, 25°C) is also studied. The maximum open-circuit voltage (Voc) and short-circuit current density (Jsc) for the cells are observed to be approximately 236 V and 7.34 mA/cm2, respectively for the n-C:P/p-Si cell grown at low Prf of 100 W. The highest energy-conversion efficiency (η) and fill factor (FF) were found to be approximately 0.84 and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.