Optoelectronic Processes in Squaraine Dye‐Doped OLEDs for Emission in the Near‐Infrared

Abstract

A novel all-organic host-guest system for emission in the NIR is introduced and investigated with respect to its opto-electronic processes. The good agreement between theoretical and experimental results highlights the model character of this system and its potential for electroluminescent application. Comparative measurements provide access to the recombination mechanisms on molecular length scale and show that the emission behavior of the device under operation is controlled by charge carrier dynamics.

Exciton Transport in Molecular Aggregates – From Natural Antennas to Synthetic Chromophore Systems

“…[223,224] The monomer and the trimer also show high fluorescence quantum yields and were used as efficient emitters in NIR OLED devices. [225,226] Again, as in the SQA cases the exciton coupling (estimated from the bandwidth) decreases slightly with the number of SQB chromophores (dimer: 800 cm −1 , trimer: 636 cm −1 , polymer: 620 cm −1 ). However, the [SQB] n polymer shows a quite unusual spectroscopic behaviour.…”

Highly Efficient Near‐Infrared Delayed Fluorescence Organic Light Emitting Diodes Using a Phenanthrene‐Based Charge‐Transfer Compound

“…However, it is still ac hallenge for researchers to develop efficient long-wavelength TADF emitters such as deep-red or near-infrared (NIR) TADF materials.T he main reason for this is because simultaneously achieving as mall DE ST value and alarge fluorescence rate (k F )inone molecule is inherently difficult through molecular design. [9] As ar esult of their potential applications in optical communication, [10] night-vision devices, [11] and sensors [12] deep-red/NIR OLEDs are attracting increasing interest. [7] Furthermore,f or deep-red/NIR emitters,t he F PL values tend to decrease as the emission wavelength increases,according to the energy-gap theory.…”

Semiconducting polymer dots with bright narrow-band emission at 800 nm for biological applications

“…46–48 In contrast with inorganic nanoparticles, one prominent advantage of Pdots is that their optical properties are highly tunable because new polymer structures can be synthesized or small molecular fluorophores can be doped into them. 49–51 For the latter case, semiconducting polymers as the nanoparticle matrix efficiently absorb light and transfer the energy to the dopant fluorophore, yielding amplified fluorescence when compared with small molecules. Recently, there are major efforts to develop NIR-emitting Pdots for biological applications.…”