Article,

Semitransparent Layers of Social Self-Sorting Merocyanine Dyes for Ultranarrow Bandwidth Organic Photodiodes

, , , , , and .
Advanced Optical Materials, 9 (15): 2100213 (May 2021)
DOI: 10.1002/adom.202100213

Abstract

Two dipolar merocyanines consisting of the same π-conjugated chromophore but different alkyl substituents adopt very different packing arrangements in their respective solid state with either H- or J-type exciton coupling, leading to ultranarrow absorption bands at 477 and 750 nm, respectively, due to exchange narrowing. The social self-sorting behavior of these push-pull chromophores in their mixed thin films is evaluated and the impact on morphology as well as opto-electronical properties is determined. The implementation of this well-tuned two-component material with tailored optical features allows to optimize planar heterojunction organic photodiodes with fullerene ​(C60) with either dual or single wavelength selectivity in the blue and NIR spectral range with ultranarrow bandwidths of only 11 nm (200 cm−1) and an external quantum efficiency of up to 18% at 754 nm under 0 V bias. The application of these photodiodes as low-power consuming heart rate monitors is demonstrated by a reflectance-mode photoplethysmography (PPG) sensor.

Tags

Users

  • @wuerthner_group

Comments and Reviews