Wavelength-selective organic field-effect phototransistors based on dye-doped poly-3-hexylthiophene

The authors present a strategy to manufacture wavelength-selective field-effect phototransistors by employing dye-doped poly-3-hexylthiophene (P3HT) as a semiconducting layer. The dye doping of the semiconductor P3HT was achieved by blending organic molecules-coumarin 6, oxazine 1, and nile red-into the conjugated organic polymer. Illuminating these transistors with monochromatic light in the range of 400-700 nm resulted in varying conductivities for certain wavelengths in dependence on the particular dye. This effect is attributed to the photogeneration of excitons on the dye molecules, which are subsequently transferred to the conjugated polymer. (c) 2006 American Institute of Physics.