Squarylium and rubrene based filterless narrowband photodetectors for an all-organic two-channel visible light communication system

In this paper, based on 1,3-bis[(3,3-dimethylindolin-2-ylidene) methyl] squaraine (ISQ), which has narrowband red-light absorption, and Rubrene, which possesses significant blue-light absorption, two color-selective organic photodetectors (OPDs) are developed. By quantum chemistry calculation, the mechanism of ISQ's sharp absorption spectrum is analyzed. Without input filtering, the two OPDs are well suited for two-channel visible light communications (VLC) system due to their good orthogonality of response spectrum and exceptional features, such as flexibility and ability to realize large-area thin-film manufacturing. With the two OPD as receivers and corresponding organic light emitting diodes (OLEDs) as data transmitters respectively, a two-channel VLC system delivering a bit-rate of 530 kb/s in the blue-light channel and 180 kb/s in the red-light channel was experimentally demonstrated. The two channels have good orthogonality when they operate together. This all-organic VLC system demonstrates the feasibility and benefit for the application of organic electronics in the communication field. (C) 2016 Elsevier B.V. All rights reserved.