Multilayer graphene films as transparent electrodes for organic photovoltaic devices

We have fabricated ITO-free organic solar cells (OSCs) based on multilayer graphene (MLG) electrodes. MLG electrodes with high transparency (∼84.2%) and low sheet resistance (∼374±3 Ω/square) were obtained on glass substrates using chemical vapor deposition and a multi-transfer process. The OSCs fabricated on MLG electrodes had an open circuit voltage of 0.52 V, a short circuit current of 6.90 mA/cm2, a fill factor of 32.6%, and a power conversion efficiency of 1.17%. The performance of the OSCs fabricated on transparent MLG electrode was not comparable to that of OSCs fabricated on ITO electrodes; cost-effective MLG electrodes are a viable alternative to sputter-grown ITO electrodes for cost-efficient and flexible OSCs.