Blended host ink for solution processing high performance phosphorescent OLEDs

Abstract

In order to solve the interface issues in solution deposition of multilayer OLED devices, a blended host concept was developed and applied to both spin-coating and inkjet printing of phosphorescent OLEDs. The blended host consists of 1,3-bis(carbazolyl)benzene (mCP) and1,3,5-tri(phenyl-2-benzimidazoly)-benzene (TPBi). Maximum current efficiency (CE) of 24.2 cd A −1 and external quantum efficiency (EQE) of 7.0% have been achieved for spin-coated device. Maximum CE and EQE of 23.0 cd A −1 and 6.7% have been achieved for inkjet printed device. The films deposited by printing and spin-casting were further researched to explore the effect of those different processing methods on device performance.

Cavity-Suppressing Electrode Integrated with Multi-Quantum Well Emitter: A Universal Approach Toward High-Performance Blue TADF Top Emission OLED

“…As a PBL with a deep HOMO level, the DPPS can effectively block holes to maintain the charge balance. The hole mobility (≈ 1.2 × 10 −4 cm 2 V −1 s −1 ) of the mCP hole-transport layer (HTL) [ 52 ] was higher than the electron mobility (≤ 10 −6 cm 2 V −1 s −1 ) of the DPPS ETL [ 53 ], which is detrimental to device performance in conventional OLEDs. However, the lower mobility of DPPS and its hole-blocking ability promote recombination at the DPPS/DMAC-DPS interface in the MQW structure.…”

Inkjet-Printed Highly Conductive Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) Electrode for Organic Light-Emitting Diodes

“…Compared with the above mentioned electrode materials, PEDOT:PSS has good film-forming ability, high transparency, tunable conductivity, flexibility and solution processability, which can be prepared via spin coating [ 13 ], inkjet printing [ 14 , 15 , 16 ], dip coating [ 17 ], spray coating [ 18 ], etc. Hence, PEDOT:PSS electrodes have been widely used in flexible optoelectronic devices, such as organic thin film transistors [ 16 ], organic solar cells [ 14 , 19 , 20 ], and OLEDs [ 7 , 15 , 21 ].…”

Solubility and Solubility Modeling of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene toward Nanodispersions in Organic Solvents

“…Organic light-emitting diodes (OLEDs) have increasingly attracted interest in the display and illumination fields , and are developing toward large-scale production and flexibility. − Solution-processed technology has been considered as a next-generation manufacturing method for OLED production. − The dispersion or solution of organic functional materials of OLEDs in solvents is critical for the preparation of inks toward solution-processed devices. , For some kinds of currently used materials that are not highly soluble in common solvents that are suitable for printing processing, their applications in solution-processed OLED devices would be limited. Theoretically, according to the Ostwald–Freundlich equation, reducing the particle size is beneficial to increase the solubility of the solute in the solvent .…”

“…7−10 The dispersion or solution of organic functional materials of OLEDs in solvents is critical for the preparation of inks toward solution-processed devices. 11,12 For some kinds of currently used materials that are not highly soluble in common solvents that are suitable for printing processing, their applications in solution-processed OLED devices would be limited. Theoretically, according to the Ostwald−Freundlich equation, reducing the particle size is beneficial to increase the solubility of the solute in the solvent.…”