Effect of Ultraviolet Light on Hybrid Zinc Oxide Polymer Bulk Heterojunction Solar Cells

Compared to conjugated polymer poly2-methoxy-5-(3',7'-dimethyloctyloxy)%-1,4-phenylenevinylene] (MDMO-PPV) solar cells, bulk heterojunction solar cells composed of zinc oxide (ZnO) nanocrystals and MDMO-PPV have a better energy conversion efficiency. However, ultraviolet (UV) light deteriorates theperformance of solar cells composed of ZnO and MDMO-PPV. We propose amodel to explain the effect of UV illumination on these ZnO:MDMO-PPV solar cells. According to this model, the degradation from UV illumination is due to a decrease of exciton dissociation efficiency. Our model is based on the experimental results such as the measurements of current density versus voltage, photoluminescence, and photocurrent.