typically made from TiO 2 , [ 3,6 ] ZnO photoanodes have emerged, in recent years, as a viable alternative. [ 7,8 ] First, ZnO fi lms feature higher electron mobilities (155 cm 2 V −1 s −1 at 300 K) and a wider band gap (3.4 eV) relative to TiO 2 fi lms. [ 7 ] Second, the ease of preparation of ZnO nanostructures compared to TiO 2 is a further asset. [ 7 ] Third, the electron injection and recombination dynamics under comparable operation conditions are similar for both types of electrodes.The most signifi cant drawbacks of ZnObased DSSCs are, however, their low stability under working conditions in acidic environments and their prominent electron loss processes. For example, injected conduction band (CB) electrons tend to recombine with either the oxidized dye or the electrolyte in close proximity to the electrode surface. In addition, low injection yields lead to relaxation processes, in which the excited dye relaxes to the ground state. The earlier and the latter, which impact the electron lifetime and the effective electron diffusion length throughout the electrode, result in poor charge collection effi ciencies. [ 9 ] Hence, research toward more effi cient and stable ZnO-based electrodes is at the forefront of investigations. [ 6 ] To tackle these aspects, different groups have demonstrated the potential of n-or p-type doping of ZnO electrodes in the context of reducing charge recombination rates-arsenic, aluminum, carbon nanotubes, gallium, graphene, lithium, potassium, tin, etc., as well as nitrogen and phosphorous are the most commonly employed doping reagents. [ 8,[10][11][12] To this end, most of the efforts have focused on zinc stannate (SZO), [ 13,14 ] reaching maximum effi ciencies of as high as 6%. [ 14 ] SZO-based devices feature high stability, good fi ll factors (FF), and high open circuit voltages ( V oc ). [ 14 ] The limiting factor is, however, the moderate short-circuit current density ( J sc ) of around 15 mA cm −2 . To achieve high effi ciencies in binary metal oxide electrodes in DSSCs, the latter calls for improvement by means of optimizing the overall charge collection effi ciency. To this end, the current work documents the optimization of indium-zinc oxide (IZO) as photoanode materials that could compete with the state-of-the-art SZO devices. Our choice of IZO is based on the fact that their fi lms feature higher electron conducting properties than SZO, [ 15 ] from which longer electron lifetimes and higher charge collection effi ciencies are expected to amplify J sc .The benefi ts of incorporating binary metal-oxide electrodes en route toward effi cient dye-sensitized solar cells (DSSCs) have recently emerged. The current work aims at realizing effi cient indium-doped zinc oxide based DSSCs by means of enhancing charge transport processes and reducing recombination rates. Electrochemical impedance spectroscopic assays corroborate that low amounts of indium reduce charge transport resistances and increase electron recombination resistances. The latter are in concert with a remark...