Characterization of indigo-doped poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester bulk heterojunction solar cells

Poly(3-hexylthiophene)/[6,6]-phenyl C61-butyric acid methyl ester bulk hetero-junction photovoltaic cells doped with indigo dye as a p-type solar collector were studied. Doping indigo increases the absorption of the visible light spectrum, as determined using ultraviolet–visible spectrophotometry analysis. The photocurrent was measured in air under a solar simulator with AM 1.5G illumination (100 mW/cm2). The best photovoltaic efficiency obtained was 2.55% after doping indigo into the cell.

► Indigo-doped organic semiconductor devices were prepared.
► Morphological change after doping favors short current density and filling factor.
► The more a doped device scatters the incident light, the more absorption is obtained.
► Crystallinity of the films is improved after indigo doping.