Review of graphene and its modification as cathode for dye-sensitized solar cells

This paper reviews the use of graphene, reduced graphene oxide (rGO) and their modification as cathode for dye-sensitized solar cell (DSSC). Graphene and rGO can be modified via several ways, namely, doping, composing and coating with other materials in order to enhance their electrical property and catalytic activity when applied in DSSC. The composite structure of graphene and rGO with other class of materials such as metal oxide, metal sulfide, alloy and conducting polymers can be formed. Metal and non-metal can be doped into graphene and rGO. Other types of material can also be coated on graphene and rGO to modify their electrical property and catalytic activity. This review highlights the performance of the device in term of power conversion efficiency (PCE) employing the modified graphene and rGO and the electrochemical impedance spectroscopy (EIS) parameters that support the PCE such as charge transfer resistance (Rct), cathodic current density (J) and incident-photon conversion efficiency (IPCE). This review also highlights the future prospects of modified graphene and rGO as cathode for DSSC.