Carbon Films for Corrosion Resistant Photoelectrochemical Cells

Abstract

Hydrogen represents an ideal source of clean energy, and a suitable power storage alternative. While there are many production methods available to produce hydrogen, they either use fossil fuels or suffer from low efficiency, detracting from any benefits this renewable energy source could provide. The purpose of this work is to fabricate a photoelectrochemical (PEC) cell that can use the energy of sunlight to power electrolysis to efficiently generate and capture hydrogen from water for use as fuel for applications such as mobile or stationary fuel cells. Most electrodes in modern PEC cells corrode fast, in less than a week, preventing the large-scale implementation of the technology. The research focuses on solving this issue by synthesizing Diamond-Like Carbon (DLC) through Plasma-Enhanced Chemical Vapor Deposition (PECVD) for use as an anti-corrosion layer and co-doping the film with Boron and Phosphorous atoms. The anticipated outcome of this work is to optimize the synthesis of DLC through PECVD and therefore to increase the lifespan of PEC cells to a range that is acceptable for industrial applications, without impeding the flow of electric current of the cell. We have shown that DLC can be synthesized at low temperature (~100°C) and the annealing enables the formation of diamond on the substrate. Moreover, the film experiences an increase in conductivity post phosphorous and boron implantation and annealing, demonstrating the effectiveness of the ion implantation method for the control of the conductivity of DLC films. The film characteristics were investigated by scanning electron microscopy (SEM), Auger Electron spectroscopy (AES), Raman spectroscopy and current-voltage (IV) measurements.