Near-infrared photodetector consisting of J-aggregating cyanine dye and metal oxide thin films

We demonstrate a near-infrared photodetector that consists of a thin film of the J-aggregating cyanine dye, U3, and transparent metal-oxide charge transport layers. The high absorption coefficient of the U3 film, combined with the use of a reflective anode and optical spacer layer, results in a zero-bias external quantum efficiency of 16.1 +/- 0.1% (lambda = 756 nm) for a device containing an 8.1 +/- 0.3 nm-thick U3 film. The specific detectivity (D*) and response speed (f(3dB)) of a fully optimized device are measured to be (4.3 +/- 0.1) x 10(11) cm Hz(1/2) W-1 and 92 kHz, respectively. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752434]