A simplified approach to thermally activated delayed fluorescence (TADF) bipolar host polymers

Abstract

Herein, we compare a series of solution-processible TADF polymers with different host pendant groups to achieve balanced charge transport properties through the combination of unipolar co-hosts.

Flexible Ink‐Jet Printed Polymer Light‐Emitting Diodes using a Self‐Hosted Non‐Conjugated TADF Polymer

“…[ 16 ] Compared to ambipolar hosts, featuring a combination of two unipolar hosts within the polymer has the advantage of enabling a simpler approach to adjust the balancing of charges by varying the monomer ratios, as well as avoiding the generally low‐yielding asymmetric synthesis. [ 20 ] For D3P‐CEC, the (monomer) synthesis is further simplified through the use of carbazole and α ‐carboline units as pendant groups replacing more complex hosts such as mCP. Additionally, many of the characteristics (including, importantly, the TADF properties) of D3P‐CEC remain unchanged and were very similar to our other self‐hosted polymers.…”

“…Additionally, many of the characteristics (including, importantly, the TADF properties) of D3P‐CEC remain unchanged and were very similar to our other self‐hosted polymers. [ 20 ] The absorption and photoluminescent (PL) spectrum of D3P‐CEC is shown in Figure 1B. D3P‐CEC has a PL peak emission at 504 nm and a full‐width half maximum (FWHM) of 91 nm.…”

“…The synthesis and characterization of the employed TADF emitter polymer was reported in our earlier work, [ 20 ] NMR, CV, and SEC data can be found in the Supporting Information. Additional NMR spectra for the monomers used in D3P‐CEC can also be found in the Supporting Information of the previous work.…”

“…Additional NMR spectra for the monomers used in D3P‐CEC can also be found in the Supporting Information of the previous work. [ 20 ]…”

Molecularly engineered host materials for high performance inkjet-printed thermally activated delayed fluorescence organic light-emitting diodes

“…However, it is difficult to design a TADF organic molecule with balanced and high carrier transport ability. [35][36][37] Similar to the approach in phosphorescent OLEDs, highly efficient TADF-OLEDs can be fabricated by dispersing the TADF emitter into a host matrix. [38][39][40] A suitable host should have not only a high triplet energy to prevent triplet-triplet annihilation, but also appropriate energy levels to facilitate efficient exciton generation.…”