Solution-Processed Green-Sensitive Organic Photoconductive Device Using Rhodamine 6G

Since rhodamine 6G (R6G) has the selective absorption band at the green wavelength regions, the green-sensitive organic photoconductive device was demonstrated using R6G as a photoconductive layer. By optimizing the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) used as the carrier transport layer and the concentration of R6G, the maximum external quantum efficiency of 32.6% was obtained at the electric field of −34 MV/m. We found that the low-conductivity of the PEDOT:PSS layer was most important factor for the improved device performance. In addition, the signal-to-noise ratio (photocurrent/dark current) was improved by reducing the conductivity of the PEDOT:PSS layer, and the highest value of 60 was achieved.