10.1021/acs.jpcc.8b02971.s001 Pom L. Kharel Pom L. Kharel Paul M. Cuillier Paul M. Cuillier Kasun Fernando Kasun Fernando Francis P. Zamborini Francis P. Zamborini Bruce W. Alphenaar Bruce W. Alphenaar Effect of Rare-Earth Metal Oxide Nanoparticles on the Conductivity of Nanocrystalline Titanium Dioxide: An Electrical and Electrochemical Approach American Chemical Society 2018 trap states undoped films Cyclic voltammograms charge transfer NTD film Doped films samples show nanocrystalline titanium dioxide enhancement mechanism electron acceptor earth oxide electron transport material Nanocrystalline Titanium Dioxide photocatalytic applications NTD performance Electrochemical Approach Doping electrochemical impedance measurements rare-earth metal oxides light sensitivity Rare-Earth Metal Oxide Nanoparticles scan rate dependence electrochemical study rare-earth oxide-doped NTD films trap regime space charge density 2018-06-13 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Effect_of_Rare-Earth_Metal_Oxide_Nanoparticles_on_the_Conductivity_of_Nanocrystalline_Titanium_Dioxide_An_Electrical_and_Electrochemical_Approach/6736607 Doping of rare-earth metal oxides into nanocrystalline titanium dioxide (NTD) films is known to improve performance for photovoltaic and photocatalytic applications; however, the reasons for this improvement are not well understood. To explore the enhancement mechanism, an electrical and electrochemical study of rare-earth oxide-doped NTD films was performed. Doped films were found to be 40–50 times more conductive than undoped films, with linear current–voltage characteristics and decreased light sensitivity. Cyclic voltammograms of doped samples show an enhanced scan rate dependence in the deep trap regime due to a slower charge trapping rate. Finally, electrochemical impedance measurements reveal a decrease in space charge density and a shift in the flat-band potential. Taken together, these results suggest that charge transfer from the rare earth oxide neutralizes the deep trap states in the NTD film, decreasing charge scattering, and improving the NTD performance as an electron acceptor and electron transport material.