Development of P-doped SiO2 as proton exchange membrane for microfuel cells

Phosphorus-doped silicon dioxide (PSG) thin films with improved ionic conductivity were deposited via plasma-enhanced chemical vapor deposition for application as a thin-film proton exchange membrane (PEM) in microfabricated fuel cells. More than three orders of magnitude improvement in the ionic conductivity is obtained by P doping of low-temperature deposited SiO2. The area resistance of 3 mu m thick film of PSG is comparable to a 200 mu m thick film of Nafion. Application of these PSG films as PEM in microfuel cells yielded more than one order of magnitude improvement in power density compared to low-temperature, undoped SiO2 membranes. (c) 2005 The Electrochemical Society.