Modeling of the J-V Characteristics for ITO/CuPc/C60/Al Hetero-Structure Solar Cells

• Published in: Journal of the Chinese Chemical Society (Taipei) 2010-10, Vol.57 (5B), p.1185-1190
• Main Authors: Wei, Shi-Zhan, Lin, Chih-Chung Chang, Ru-Hau, Lin, Ku-Yen, Jong, Ming-Nan, Juey, Liu-Ting, Chiu, Kuan-Cheng
• Format: Article
• Language: English
• Subjects: Equivalent circuit; J-V Characteristics; Modeling; Organic photovoltaic cells
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.201000172

The characteristics of current density (J) versus bias voltage (V) for various organic photovoltaic cells (OPVCs) with a basic hetero‐structure of ITO/CuPc/C60/Al are measured and analyzed by an equivalent circuit model. Two modeling schemes are developed and analyzed. The first one involves the direct fit of the J‐V data to the equation governed by the equivalent circuit. But for some of the J‐V data, the direct‐fit scheme occasionally leads to unrealistic fitting values. To maximize the usefulness of the equivalent circuit, a second modified scheme is then proposed and justified. Finally, together with experimental J‐V data and numerical fitting results, effects from the adding of C60 hetero‐junction layer and from the changing of substrate temperature during the deposition of CuPc layer are discussed for various OPVCs. Comparison of the fitting results by direct fit to Eq. (1) (the red curve) and by modified scheme (the green curve, which is identical to the red curve for V > Voc). The constant value of Rsh adopted in modified scheme is evaluated by the differential resistance in the negative bias region as depicted in the inset (the blue line). (Special Issue for the 2009 International Symposium of Dye‐Sensitized Solar Cells)