Nanostructure determines the intensity-dependence of open-circuit voltage in plastic solar cells

作者：Reid Obadiah G^*; Xin Hao; Jenekhe Samson A; Ginger David S

来源：Journal of Applied Physics, 2010, 108(8): 084320.

DOI：10.1063/1.3482009

We use photoconductive atomic force microscopy to make local measurements of the open-circuit voltage (V(OC)) as a function of light intensity in several polymer/fullerene bulk heterojunction blend solar cells. We find significant local variations in the slope of the open-circuit voltage plotted versus the log of the light intensity. By studying a model alkoxy-poly (p)-pheneylene-vinylene/phenyl-C(61)-butyric acid methyl ester system with known vertical structure, and by comparing our results with a simple numerical model, we associate these local differences in V(OC) versus light intensity with lateral variations in vertical morphology/composition. These results not only provide a qualitative method of mapping lateral variations in vertical structure/composition by making local measurements of V(OC) as a function of light intensity but suggest that the unusual light-intensity dependence of V(OC) (diode ideality factors in the light) of many organic photovoltaics can be linked with morphological heterogeneity.

• 出版日期2010-10-15