Enhancement in efficiency and optoelectronic quality of perovskite thin films annealed in MACl vapor
We analyzed and compared quantitatively the optoelectronic characteristics of perovskite PV devices with and without annealing the perovskite layer in a methyl ammonium chloride vapor atmosphere (MACl treatment). We found that the MACl treatment resulted in the mitigation of defect states, reduced defect density, improvement in the carrier profile, and passivation of recombination activities, which we infer as natural consequences of significantly improved film quality with better crystallinity and grain morphology of the perovskite layer. MACl-treated devices are more efficient with the best efficiency of ∼15.1% with small standard deviation (std.) (0.50%) and improved stability compared to devices without MACl treatment having the best efficiency of 12.4% with std. of 0.66%.