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Abstract:
Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4 '-(N-(4-butylphenyl))] (TFB), one of the most popular and widely used hole-transport layer (HTL) materials, has been successfully applied in high performance spin-coated quantum dots-based light-emitting diodes (QLEDs) due to its suitable energy level and high mobility. However, there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL. TFB normally suffers from the interlayer mixing and erosion, and low surface energy against the good film formation. Here, a novel environment-friendly binary solvent system was established for formulating quantum dot (QD) inks, which is based on mixing halogen-free alkane solvents of decalin and n-tridecane. The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3, at which a stable ink jetting flow and coffee-ring free QD films could be formed. To research the influence of substrate surface on the formation of inkjet-printed QD films, TFB was annealed at different temperatures, and the optimum annealing temperature was found to enable high quality inkjet-printed QD film. Inkjet-printed red QLED was ultimately manufactured. A maximum 18.3% of external quantum efficiency (EQE) was achieved, reaching 93% of the spin-coated QLED, which is the best reported high efficiency inkjet-printed red QLEDs to date. In addition, the inkjet-printed QLED achieved similar T-75 operational lifetime (27 h) as compared to the spin-coated reference QLED (28 h) at 2,000 cd center dot m(-2). This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.
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NANO RESEARCH
ISSN: 1998-0124
Year: 2021
Issue: 11
Volume: 14
Page: 4125-4131
1 0 . 2 6 9
JCR@2021
9 . 6 0 0
JCR@2023
ESI Discipline: PHYSICS;
ESI HC Threshold:87
JCR Journal Grade:1
CAS Journal Grade:1
Cited Count:
WoS CC Cited Count: 35
SCOPUS Cited Count: 16
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 1
Affiliated Colleges: