PLASMA-ASSISTED CHEMICAL VAPOR DEPOSITION OF Fe:TIO_2 FILMS FOR PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION

摘要

Fe-doped TiO_2 (Fe:TiO_2) thin films were deposited onto fluorine-doped tin oxide (FTO, SnO_2:F), substrates via plasma enhanced chemical vapor deposition (PE-CVD) using a stoichiometric mixture of iron pentacarbonyl (Fe(CO)_5) and titanium isopropoxide (Ti(OPr)_4) as precursors. The evolution of surface morphology with changing process parameters was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). UV-Visible spectral data showed a shift of the absorption edge towards the visible region and the band gap energy was found to gradually decrease with increasing dopant (Fe) concentration. Photoelectrochemical (PEC) measurements carried out on Fe:TiO_2 samples under 1 Sun illumination using 1M NaOH as electrolyte showed maximum photocurrent density and flatband potential of 1.26 mA/cm~2 and 0.68V/SCE, respectively at 5.0 at% Fe doping. Incident photon-to-electron conversion efficiency (IPCE) was found to increase from 0.75% to 4.0% upon increasing the dopant concentration upto 5.0 at%.