High Efficiency and Long Lifetime of a Fluorescent Blue-Light Emitter Made of a Pyrene Core and Optimized Side Groups

Abstract

In this study, four emitters of blue light are synthesized by selecting pyrene with its high photoluminescence quantum yield (PLQY) as the core group and variants of the electron-donating diphenylamine (DPA) as side groups. The four compounds have different numbers, sizes, and substitution positions of alkyl groups on the DPA. Each of the four compounds when doped in OLED devices shows a high current efficiency (CE) of over 7 cd A and a high external quantum efficiency (EQE) of over 7.5%. In addition, the compounds yield electroluminescence (EL) spectra showing peaks with narrow full width at half-maximum (fwhm) values of 37-40 nm and hence indicative of high color purity. Moreover, one compound N1,N6-bis(5-( tert-butyl)-2-methylphenyl)-N1,N6-bis(2,4-dimethylphenyl)pyrene-1,6-diamine (3Me-1Bu-TPPDA), shows a very high EQE of 9.25% and a very long lifetime with an LT95 of 471 h.

Thermally Activated Delayed Fluorescence Materials: Towards Realization of High Efficiency through Strategic Small Molecular Design

“…At the deposition temperature of 200 K, the corresponding film exhibited the highest PLQY of 0.736±0.005, evidently due to the horizontal orientation caused by linear‐shaped PXZ‐TRZ. Similar results were also obtained with DACT‐II, which features 100 % conversion from electricity to light. The DACT‐II was found to be more likely to be parallel to the substrate, with the order parameter S of −0.32±0.01.…”

P‐184: Boron Derivatives as Deep Blue Fluorescent Materials for High Efficiency and Long Lifetime

“…The pyrene derivatives are light emitters which have a pyrene core structure modified with an aromatic amine-based auxochromophore and emit deep blue light. [8] High EQE, deep blue emission color, and long lifetime were features observed in the deep blue fluorescent OLED utilizing the pyrene derivatives as emitters. In addition to pyrene derivatives, anthracene blue emitters, styrylbenzene-type blue emitters and fluorene-based emitters have been reported as high EQE blue fluorescence emitters.…”

Ab initio study on the excited states of pyrene and its derivatives using multi-reference perturbation theory methods

“…1 These properties can be tailored to meet specic requirements through modications of its chemical structure; [2][3][4][5][6][7][8][9][10][11] therefore, pyrene derivatives are recognized as promising materials for organic light-emitting devices. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] Pyrene is also well known for the formation of an excimer. [26][27][28][29] An aromatic excimer is a dimeric complex of the same aromatic molecules that is formed in the excited state.…”