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

Abstract

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% (λ = 756 nm) for a device containing an 8.1 ± 0.3 nm-thick U3 film. The specific detectivity (D*) and response speed (f [subscript 3 dB]) of a fully optimized device are measured to be (4.3 ± 0.1) × 10[superscript 11] cm Hz[superscript 1/2] W[superscript −1] and 92 kHz, respectively.