Research activities focused on the attempts to improve figures for photocurrents of the whole cell by replacing the indium-tin-oxide (ITO) top electrode with a W-doped In2O3 (IWO) top contact was deposited by radio-frequency sputtering. By modifying the deposition parameters of this material, very high charge carrier mobilities were achieved, allowing the sample to be more transparent while not losing any conductivity. With this new top TCO, significant gains in transparency were achieved along with gains in the photocurrent values. In addition to the gain in transparency, the new top contact had the unexpected side benefit of improving open-circuit voltage (V_OC) in the devices. Exploring this further, it became evident that the sputtering power used in this layer was responsible for this increase in V_OC which could be repeated across a number of other transparent conductive oxide (TCO) materials. Using IWO as an improved top contact along with small optimisations to the perovskite layer thickness to improve current matching, a new champion device with a demonstrated efficiency of 25.4% was fabricated (steady-state, 26.0% in light-current voltage (LIV).