Small-molecular organic solar cells with C60/Al composite anode

By adopting C60/Al composite anode and an inverted device structure of ITO/Alq3/C60/CuPc/C60/Al, we have achieved a power conversion efficiency of 0.78% under 75 mW/cm2 AM1.5G simulated illumination and a shelf lifetime of 950 h from unencapsulated organic solar cells. The improved stability is attributed to efficient protection of the C60 layer in the inverted structure. Replacing the C60/Al anode with C60/Au anode in the inverted structure, produces a power conversion efficiency of 0.64%, comparable to that of the device with C60/Al anode. This indicates that the property of the composite electrode is mainly determined by the thin C60 layer. Use of C60/Al composite anode to fabricate inverted organic light-emitting devices gives rise to an efficiency of the device comparable to that of conventional devices.