Delafossite CuGaO₂ is a p-type metal oxides which can be used as hole transport layers in a wide range of heterojunction solar cells. These materials are interesting because of their crystal structure that can facilitate hole diffusion through the valance band and a potential alternative to NiO as an HTM because of its more favorable band position to typical redox mediator, and its greater transperancy to visible light. Here we have investigated the effect of post synthetic annealing conditions on electrochemical properties of CuGaO₂ nanocrystalline thin films in acetonitrile solution with LiClO₄ electrolyte and iodide triiodide redox mediator. These metal oxide nanocrystals have defects intrinsic to their structure and those can be increased or remediate by different annealing atmosphere. In this work, CuGaO₂ was synthesized by hydrothermal method and nanocrystalline films were produced by dispersion of CuGaO₂ nanocrystals in a polymer solution designed to control the porosity of the resulting film. We have used four different chain lengths of ethyl cellulose polymers (10, 22, 100 and 300 cP) to understand their impact on film morphology and photocurrent. Electrochemical impedance spectroscopy (EIS) was used to probe the electrochemical behavior and capacitance of the films. The films were prepared by spin coating and annealed initially under Ar environment at 350⁰C. We have used I^-/I₃^- redox mediator to observe the comparative photocurrent under white light LED. We have used two other different annealing atmospheres H₂ and O₂ after the pre-Argon annealing step to compare the photocurrent and observed the highest photocurrent by annealing under H₂ gas. We assume, this is due to remediating some of the defect states under reducing atmosphere. We have compared two different synthetic pH for CuGaO₂ (pH 5 and 9).We have measured the film thickness and using the data from dye load experiments, the porosity of the films were calculated to get the idea about the best quality film in terms of photocurrent . Among four different chain lengths of polymer, the films prepared from shorter chain polymers show comparatively higher photocurrent.