Application of graphene in tandem organic solar cells

A highly conductive and transparent graphene film is deployed as an efficient intermediate layer (IML) in tandem organic photovoltaic cells. Tandem cells utilizing transition metal oxide modified graphene IML demonstrate a high open circuit voltage (V
_oc
) of 1.13 V in series connection. The value of V
_oc
from tandem cell is very close to the sum of V
_oc
attained from two individual subcells (0.58 V) that confirms the perfect ohmic contact at the photoactive layer/graphene interface. The UPS result showed the work function of graphene can be increased effectively to ensure good charge collection with different thickness of MoO
₃
layer.