Highly efficient exciplex-emission from spiro[fluorene-9,9′-xanthene] derivatives

Cao, Hong‐Tao; Wan, Jun; Li, Bo; Zhang, He; Xie, Linghai; Sun, Chen; Feng, Quanyou; Yu, Wen-Jing; Huang, Wei

doi:10.1016/j.dyepig.2020.108894

Cited by 13 publications

(5 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More importantly, an excellent η ext of 25.8% is simultaneously achieved in device C . It can be observed from Table and Figure S41 that this η ext value is one of the best efficiency values among the reported exciplex-OLEDs. ,,,− Naturally, these excellent EL performances are believed to result from the promising PLQYs of TAPC:2 as well as the structure optimization of device C . More than that, it means that the hindrance increase strategy in the acceptor is beneficial to harvesting higher EL efficiencies for the exciplex systems.…”

Section: Resultsmentioning

confidence: 87%

“…Subsequently, they performed optimization of the device structure and obtained a high η ext of 26.4% . To date, a series of electron acceptors, such as N -heteroarene/heterocycle, arylborane, triazine, diphenylphosphine oxide, oxadiazole, etc., have been designed and synthesized for exciplex-TADF. ,,, Some of the reports have obtained excellent η ext values over 20%, − but most of them still have values less than 25%, which are far behind those of pure TADF − and phosphorescent materials. , Kim et al recently adopted 4,6-bis[3,5-(dipyrid-4-yl)phenyl]-2-methylpyrimidine (B4PYMPM) as an electron acceptor combined with 4,4′,4″-tris( N -carbazolyl)-triphenylamine (TCTA) as an electron donor and achieved a peak η ext of 25.2% at a temperature of 150 K . However, the η ext value decreased to 11.0% when the temperature was 300 K. So, exceeding 25% in external quantum efficiency at room temperature is still difficult and considered as a challenge for exciplex-TADF …”

Section: Introductionmentioning

confidence: 99%

“…Moreover, it is suggested that donor–acceptor (D–A)-type electron acceptor materials are helpful in the exciplex formation process and in improving exciplex emission efficiencies. , So, selecting D and A fragments in a fluorene-based structure to construct D–A (or A–D–A)-type electron acceptors is important. However, reports of such electron acceptors for exciplex-TADF are still limited. ,, …”

Section: Introductionmentioning

confidence: 99%

“…However, reports of such electron acceptors for exciplex-TADF are still limited. 27,30,42 Herein, we report a steric hindrance increase strategy to design 9-phenylfluorene based D−A-type electron acceptors for exciplex-TADF. As depicted in Scheme 1, we select 9phenylfluorene to construct the molecular skeleton, simultaneously adopting cyano as the electron-withdrawing (A) group.…”

Section: ■ Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Enhanced Efficiency of Exciplex Emission from a 9-Phenylfluorene Derivative

Cao

Hou

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

The exciplex-thermally activated delayed fluorescence (exciplex-TADF) system is an excellent candidate for the fabrication of high-efficiency organic light-emitting diodes (OLEDs) because of its more easily achieved small singlet–triplet energy splitting (ΔE ST) and doping control. However, exciplex-TADF is still faced with the problems of low external quantum efficiency (ηext) and unclear effect of structure modification in electron acceptors. Herein, we provide a steric hindrance increase strategy to obtain high-efficiency exciplex emissions. Through introducing a 9-phenylfluorene group into N-ethylcarbazole of the dicyano-substituted 9-phenylfluorene, an electron acceptor material with increased steric hindrance is obtained, which helps the exciplex harvest a larger driving force and higher emission efficiencies. Encouragingly, the obtained OLED displays a maximum ηext of 25.8%, which is one of the best efficiency values among reported exciplex-OLEDs, simultaneously possessing excellent current efficiency of 83.6 cd A–1 and power efficiency of 93.7 lm W–1. It is expected that this work will offer a new avenue for designing electron acceptors for highly efficient exciplex emissions.

show abstract

Section: Resultsmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhanced Efficiency of Exciplex Emission from a 9-Phenylfluorene Derivative

Cao

Hou

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…Several routes for the synthesis of xanthene derivatives using heterogeneous catalysts have been published in the literature, but have shown to have limitations such as variable yields (0%–96%) ( Yang et al, 2019 ; Ghamari Kargar et al, 2021 ; Wei et al, 2022 ), variable reaction times (10 min–24 h) ( Venkatesan et al, 2008 ; Lee et al, 2020 ; Cao et al, 2021 ) and potentially harsh reaction conditions. ( Ilangovan et al, 2011 ; Ghafuri et al, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Continuous flow catalysis with CuBTC improves reaction time for synthesis of xanthene derivatives

Thai,

Roach,

Reynolds

2023

Front. Chem.

View full text Add to dashboard Cite

The copper-based metal-organic framework (MOF) CuBTC (where H3BTC = benzene-1,3,5-tricarboxylate) has been shown to be an efficient heterogeneous catalyst for the generation of 1,8-dioxo-octa-hydro xanthene derivatives, which are valuable synthetic targets for the pharmaceutical industry. We have applied this catalytic capability of CuBTC to a continuous flow system to produce the open chain form of 3,3,6,6-tetramethyl-9-phenyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, a xanthene derivative from benzaldehyde and dimedone. An acid work-up after producing the open chain form of the xanthene derivative was used to achieve ring closure and form the final xanthene product. The CuBTC used to catalyze the reaction under continuous flow was confirmed to be stable throughout this process via analysis by SEM, pXRD, and FT-IR spectroscopy, elemental analysis, and XPS. The reaction to produce the open-chain form of the xanthene derivative produced an average yield of 33% ± 14% under the continuous flow (compared to 33% ± 0.12% of performing it under batch conditions). Based on the data obtained from this work, the continuous flow system required 22.5x less time to produce the desired xanthene derivative at comparable yields to batch reaction conditions. These results would allow for the xanthene derivative to be produced much faster, at a lower cost, and require less personal time while also removing the need to perform catalyst remove post reaction.

show abstract

Designing Host Materials for the Emissive Layer of Single‐Layer Phosphorescent Organic Light‐Emitting Diodes: Toward Simplified Organic Devices

Poriel

Rault‐Berthelot

2021

Adv Funct Materials

View full text Add to dashboard Cite

Thanks to the tremendous effort over the last 20 years, phosphorescent organic light‐emitting diodes (PhOLEDs) represent a prevalent technology. In this technology, all the high‐efficiency PhOLEDs are multi‐layer devices constituting, in addition to the emissive layer (EML), of a stack of functional organic layers. These layers play a crucial role in the device performance as they improve the injection, transport, and recombination of charges within the EML. Single‐layer PhOLEDs (SL‐PhOLEDs) represent ideal OLEDs, consisting only of the electrodes and the EML. However, reaching high‐performance SL‐PhOLED is far from easy, as removing the functional layers of an OLED stack dramatically decreases the performance. To achieve high SL‐PhOLED efficiency, the efficient injection, transport, and recombination of charges should be insured by the EML, and particularly, by the host material. In the present exhaustive review, the different molecular design strategies are analyzed, which have been used to construct high‐efficiency hosts for SL‐PhOLED. The impact of the electronic properties (triplet energy, HOMO/LUMO energy, mobility etc.) on the device characteristics (threshold voltage, electroluminescent spectrum, external quantum efficiency, etc.) are discussed. This allows to draw a structure/properties/device performance relationship map of interest for the future design of functional materials for SL‐PhOLEDs.

show abstract

Highly efficient exciplex-emission from spiro[fluorene-9,9′-xanthene] derivatives

Cited by 13 publications

References 56 publications

Enhanced Efficiency of Exciplex Emission from a 9-Phenylfluorene Derivative

Enhanced Efficiency of Exciplex Emission from a 9-Phenylfluorene Derivative

Continuous flow catalysis with CuBTC improves reaction time for synthesis of xanthene derivatives

Designing Host Materials for the Emissive Layer of Single‐Layer Phosphorescent Organic Light‐Emitting Diodes: Toward Simplified Organic Devices

Contact Info

Product

Resources

About