The Si resistances obtained for devices with c-TiO2 and SiOx protection layers were compared to those from both the Voight and Maxwell fit for devices with a-TiO2 protection layers. Figure shows these results for potentials from -0.30 V to -0.60 V vs RHE, with 5 replicates per device type. For this potential range and illumination intensity, all devices have reached the saturation current regime. As shown, using the Maxwell circuit for a-TiO2 protected devices gives Si resistances consistent with the unambiguous values obtained for SiOx and c-TiO2 protected devices. Alternatively, using the Voight circuit for a-TiO2 protected devices results in values that are over an order of magnitude less. Although results have so far focused on devices under 0.1 sun illumination for ease of analysis, these conclusions are maintained for higher light intensities as shown in Figure .