▎ 摘　　要

NOVELTY - The series tandem organic photovoltaic cell (100) has an a graphene intermediate layer (105) that is formed between a first photoactive sub-cell (110) and a second photoactive sub-cell (115). The graphene intermediate layer collects charges generated from the first and second photoactive sub-cells. Preferably, the graphene intermediate layer has a sheet resistance that is less than 1000 ohms per square. Preferably, the intermediate layer has an optical transparency that is greater than 80%. USE - Series tandem organic photovoltaic cell for portable electricity source e.g. charger for portable electronic device. Uses include but are not limited to mobile phone, digital camera, handheld game machine, or notebook computer. ADVANTAGE - Eliminates optical light loss problem associated with conductive metallic thin films, and allows use of a single substrate for each photoactive sub-cell by using graphene intermediate layer. Allows use of graphene intermediate layer with a tunable work function that enables an easy match-up with the energy levels of the photoactive layers of the photoactive sub-cells used in tandem photovoltaic cells, thus improving solar cell efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a tandem optoelectronic device; and (2) a method of fabricating a tandem organic photovoltaic cell. DESCRIPTION OF DRAWING(S) - The drawing shows the schematic diagram of a series tandem organic photovoltaic cell in which a graphene intermediate layer is interposed between two photoactive sub-cells. Series tandem organic photovoltaic cell (100) Graphene intermediate layer (105) First photoactive sub-cell (110) Second photoactive sub-cell (115) Electrode (160)