Dyes, organic infrared

Binda M, Agostinelli T, Caironi M, Natali D, Sampietro M, Beverina L, Ruffo R, Silvestri F (2009) Fast and air stable near-infrared organic detector based on squaraine dyes. Org Electron 10 1314-1319... 

Triarylmethane Dyes with Near-Infrared Absorption. The long wavelength absorption bands of triarylmethane dyes can be shifted into the near-infrared region, but the dyes still remain colored because other absorption bands are shifted to or stay in the visible region. These types of triarylmediane dyes and their derivatives have been claimed as infrared absorbers for optical information recording media and security devices, and as organic photoconductors for nse in lithographic plate production. 

Martoglio et al. (75, 16) and Jakes et al. (77) used microspectroscopy to find evidence of dyes, but the results were inconclusive due to the small sample size, and the lack of a comparative dye plant collection and associated spectra. Sibley and Jakes (18) researched the colored textiles of Etowah burial 57. Since it contained no iron, the iron-containing minerals that are thought of as ochre1 could not have been the source of the colorant. Furthermore, the researchers found organic bands in infrared spectra of these fibers that revealed not only the proteinaceous nature of the mineralized fibers, but also other bands that were attributed to dye. 

Similarly in the case of organic solar cells, the low optical absorbance in the red/near-infrared region of the dyes commonly used in DSSCs such as ruthenium bipyridyl [276] has prompted the incorporation of Pcs in these devices [277,278],... 

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