The model determined the surface coverage of solution-processed film on perovskite. Calculated surface density map provides insight into morphology of the monolayer. Carbonyl oxygen atom of PCBM strongly attaches to the (110) surface of perovskite. Uniform distribution of clusters on perovskite surface at lower PCBM concentration. Deposition rate of PCBM on the surface is very high at initial stage of film growth.