Wavelength sensitive photodiodes in the visible based on J-type aggregated films patterned by inkjet method

In this study, a kind of disposable and miniaturized organic photodiodes in the visible has been developed based on the J-type aggregated cyanine dyes films by the drop-on-demand inkjet method. Wavelength sensitivity has been found by measuring the open-circuit voltage (Voc) of the organic photodiodes under the excitation of laser pulses at various wavelengths and high spectral resolution around the absorption peak of each cyanine dye J-aggregates can be obtained, where a sharp decrease on the Voc and a Voc in reverse direction are observed. The mechanism responsible for the sharp decrease and reverse Voc are discussed and the feasibility of using the laser output from a solid-state dye laser waveguide as the excitation source for the organic photodiodes which may be possibly integrated together onto the flow-cytometry chips in the future are also demonstrated.