Composition-dependent phase separation effects of organic solar cells using P3HT:PCBM as active layer and chromium oxide as hole transporting layer

▶ With the help of the UV/visible spectrophotometer, optical microscopy and scanning electron microscope, we found that the cluster of PCBM at the interface or surface was affected by Al cathode, the composition of the blends and thermal annealing. ▶ Organic solar cells (OSCs) based on blends of poly (3-hexylthiophene) and fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester have been fabricated with p-type chromium oxide film as hole-transporting layer, which has not reported. ▶ The disc-like shape crystals of PCBM substituted for the needle-like ones at higher PCBM compositions at the ATL/Al interface, which led to stronger contacts and bigger.