THE INFLUENCE OF TIO2 DOPING ON THE QUANTUM EFFICIENCY OF ALPHA-FE2O3ELECTRODES IN WATER PHOTOELECTROLYSIS

The doping effects of titanium dioxide (TiO2) on the photoresponse of polycrystalline alpha-Fe2O2 electrodes in the range 0.01-0.14 atomic p ercent (a/o Ti4+) were investigated the optimal efficiency of the ligh t conversion into electricity occurred at about 5 x 10(19) cm-3 donors concentration. The donors concentration has been estimated from the M ott-Schottky plots. The spectral sensitivity of TiO2 doped alpha-Fe2O3 electrodes was studied, also showing an increased quantum yield of th e electron-hole pair generation for higher donor concentrations. The m aximum of adsorption did not shift significantly toward shorter wavele ngths up to 5.3 X 10(19) cm-3 donor concentration.