Ultrathin PCBM layer improve efficiency for organic solar cell

To study the effect of ultrathin PCBM on organic solar cell,two different kinds of bulk heterojunction batteries were prepared,one of which contained ultrathin PCBM layer and the another one without ultrathin PCBM layer.Cells possess structures as ITO/PEDOT:PSS/P3HT+PCBM/PCBM/Al,ITO/PEDOT:PSS/P3HT+PCBM/Al,respectively.Experiment results indicate that cell's open-circuit voltages are 0.599 2 V and 0.572 7 V,respectively,the power conversion efficiency are 2.24% and 1.21%,respectively.The PCBM layer has the action of electron-transporting.