Thieno[3,4-c]pyrrole-4,6-dione as novel building block for host materials for red PhOLEDs

Abstract

aIn the presented work the electron accepting thieno [3,4-c]pyrrole-4,6-dione is introduced as a novel building block for donor-acceptor based host materials for Phosphorescent Organic Light Emitting Diodes (PhOLEDs). A series of three regioisomers consisting of the thieno[3,4-c]pyrrole-4,6-dione acceptor and carbazole donors linked via a phenylene linker was prepared and the impact of the phenylene substitution pattern on the molecular properties was analyzed. Regarding their applicability as host materials, the newly developed materials were investigated in red PhOLED devices achieving a high current efficiency of 30.6 cd A À1 corresponding to an external quantum efficiency of 17.7% and a high power efficiency of 23.8 lm W À1. Thus, we present the first successful application of the thieno[3,4-c]pyrrole-4,6-dione building block in host materials for PhOLEDs.

Purely Spin‐Vibronic Coupling Assisted Triplet to Singlet Up‐Conversion for Real Deep Blue Organic Light‐Emitting Diodes with Over 20% Efficiency and y Color Coordinate of 0.05

“…The absorption bands below 370 nm are assigned to the 𝜋-𝜋 * transitions of the fused molecular structure, [29] whereas those between 370 and 450 nm are attributed to the n-𝜋 * transitions of the ICz part. [30] Optical gaps were evaluated from absorption onsets of 2.84, 2.79, and 2.72 eV for BisICz, tBisICz, and tPBisICz, respectively. The photoluminescence (PL) spectra of the emitters were collected from the thin films (Figure 3a).…”

Acceptor modification of diindolocarbazole embedded multiple-resonance emitters for efficient narrowband deep-blue OLEDs with CIEy ≤ 0.08 and alleviated efficiency roll-off

“…42–44 The absorption bands below 370 nm are assigned to the π–π* transitions of the fused molecular structure, 56 whereas those between 370 nm and 450 nm are attributed to the n–π* transitions of the ICz part. 57 The Fl spectra of pICz-PPO and pICz-2PPO exhibit narrowband deep-blue emissions peaking at 438 nm and 439 nm, respectively. It can be noticed that there is a shoulder band at a lower energy (∼475 nm) for both emitters, as already observed for some reported multiresonance molecules.…”

Development of a Library of Novel Compounds for Use in Organic Solar Cells

“…221,348,426,427 It was hoped that slow film formation would allow sufficient time for nucleation and increased crystal growth of P3HT. 122 The standard method of film formation until this point involved: pipetting a solution onto the ITO substrate; spinning at the desired spin speed for 25 seconds; removing the substrate from the spin coater and placing on a clean surface; and immediately covering with a 12 cm glass Petri dish. The films appeared predominately dry when taken off the spin coater; however the Petri dish was employed as to create a more tightly controlled environment (in comparison to ambient glove box atmosphere) if any further film drying was to occur.…”