This work reports the study of solvent effects on the morphology for P3HT/PCBM films using chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene. Although extensive research has been focused on investigating devices using chlorobenzene and 1, 2-dichlorobenzene and it was found that 1, 2-dichlorobenzene led to an improved device performance, little work has been conducted in the morphology by comparing films fabricated via chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene. Atomic force microscopy (AFM) was performed to study the film morphology using chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene as solvents. Initial studies showed that the size of nanocrystallites in 1, 2-dichlorobenzene based films is smaller than nanoclusters in the other two films. Kelvin probe force microscopy (KFM) images, which were used to figure out the electron transport pathway, together with AFM images, showed the solvent effect on the morphology of these films. In addition, obvious red shifts were observed in the UV-Vis absorption spectra for the P3HT/PCBM blend from 1, 3-dichlorobenzene and 1, 2-dichlorobenzene compared to the one from chlorobenzene.