Effect of carbon electrode annealing temperature on the performance of n-i-p perovskite solar cells

Perovskite solar cells (PSCs) have shown an outstanding performance improvement since their first introduction. Currently, high-performing PSCs still utilize gold, silver, or platinum as their counter electrode which can hinder the path of commercialization. Thus, carbon is introduced as an alternative counter electrode for PSC. Usually, to utilize a carbon counter electrode, carbon powder was made into a paste and then deposited onto the substrate. The substrate is then heated to evaporate the solvent and become a compact carbon layer. Research related to carbon annealing temperature was already conducted by another researcher, but their structure was mesoscopic where the carbon layer was deposited before the perovskite layer. In this research, we investigate the effect of the annealing temperature of carbon counter electrode in PSC. It was found that as the annealing temperature was increased, the PSC’s performance decreased. This might be caused by the change in perovskite crystal. From the experiment, a carbon annealing temperature of 80^oC gives the best PSC performance with V_OC of 0.90 V, J_SC of 9.44 mA/cm², fill factor of 0.40, and power conversion efficiency of 3.36%. These results provide consideration on the preference of annealing temperature of a layer that deposited after perovskite, especially for carbon counter electrode.