Enhanced Luminescent Properties of TADF-OLEDs Based on Device Structures

LIU Ting-ting; LI Shu-hong; WANG Wen-jun; LIU Yun-long; DU Hui; WANG Qing-lin; ZHAO Ling; G

doi:10.3788/fgxb20204101.0077

您当前的位置：

首页 >

文章列表页 >

Enhanced Luminescent Properties of TADF-OLEDs Based on Device Structures

Device Fabrication and Physics | 更新时间：2020-08-12

- Enhanced Luminescent Properties of TADF-OLEDs Based on Device Structures
- Chinese Journal of Luminescence Vol. 41, Issue 1, Pages: 77-85(2020)
- 作者机构：
  
  1. 聊城大学物理科学与信息工程学院, 山东聊城 252059
  2. 山东省光通信科学与技术重点实验室,山东聊城,252059
- 作者简介：
- 基金信息：
  
  Supported by National Natural Science Foundation of China(61775089);Industrial All
- DOI：10.3788/fgxb20204101.0077
  CLC： TN383+.1
- Received：06 August 2019，
  
  Revised：17 September 2019，
  
  Published Online：08 October 2019，
  
  Published：05 January 2020
- 稿件说明：
移动端阅览
刘婷婷, 李淑红, 王文军等. 基于器件结构提高TADF-OLED器件的发光性能[J]. 发光学报, 2020,41(1): 77-85

LIU Ting-ting, LI Shu-hong, WANG Wen-jun etc. Enhanced Luminescent Properties of TADF-OLEDs Based on Device Structures[J]. Chinese Journal of Luminescence, 2020,41(1): 77-85
刘婷婷, 李淑红, 王文军等. 基于器件结构提高TADF-OLED器件的发光性能[J]. 发光学报, 2020,41(1): 77-85 DOI： 10.3788/fgxb20204101.0077.

LIU Ting-ting, LI Shu-hong, WANG Wen-jun etc. Enhanced Luminescent Properties of TADF-OLEDs Based on Device Structures[J]. Chinese Journal of Luminescence, 2020,41(1): 77-85 DOI： 10.3788/fgxb20204101.0077.

摘要

为了提高以TADF材料作为主体、天蓝色荧光材料作为客体的混合薄膜的OLED器件光电性能，我们调整了器件结构，使主体材料发挥其优势。制备了基本结构为ITO/NPB（40 nm）/DMAC-DPS:

% BUBD-1（40 nm）/Bphen（30 nm）/LiF（0.5 nm）/Al的OLED器件。研究了主-客体材料在不同掺杂浓度下的OLED器件的光电特性。为了提高主体材料的利用率，在空穴传输层和发光层之间加入10 nm的DMAC-DPS作为间隔层；然后，在阳极和空穴传输层之间加入HAT-CN作为空穴注入层，形成HAT-CN/NPB结构的PN结，有效降低了器件的启亮电压（2.7 V）。测量了有无HAT-CN的单空穴器件的阻抗谱。结果表明，在最佳掺杂比例（2%）下，器件的外量子效率（EQE）达到4.92%，接近荧光OLED的EQE理论极限值；加入10 nm的DMAC-DPS作为间隔层，使得器件的EQE达到5.37%；HAT-CN/NPB结构的PN结有效地降低了器件的启亮电压（2.7 V），将OLED器件的EQE提高到5.76%；HAT-CN的加入提高了器件的空穴迁移率，降低了单空穴器件的阻抗。TADF材料作为主体材料在提高OLED器件的光电性能方面具有很大的潜力。

Abstract

In order to improve the optoelectronic properties of organic light emitting diodes (OLEDs) with a hybrid film as the light emitting layer

which included the thermally activated delayed fluorescent (TADF) as host matrix and the sky-blue fluorescent material guest

we adjusted the device structures properly to improve the utilization rate of the host material. The basic structure of OLED is ITO/NPB(40 nm)/DMAC-DPS:

% BUBD-1(40 nm)/Bphen(30 nm)/LiF(0.5 nm)/Al. First

the optoelectronic properties of host-guest OLED devices was studied with different doping ratio. Then

the DMAC-DPS (10 nm) was evaporated between the hole transport layer and the emission layer

it improved the utilization rate of the host material. Moreover

an organic material HAT-CN was added as the hole injection layer between the anode and the hole transport layer with the method of vacuum evaporation. Finally

the hole-only devices with or without HAT-CN were fabricated for the impedance spectra. The results indicated that the external quantum efficiency (EQE) of 4.92% was acquired at the optimal doping ratio (2%)

it approached the theoretical EQE limit of the fluorescent OLEDs. The DMAC-DPS (10 nm) between the hole transport layer and the emission layer improved the utilization rate of the host material

led to a higher EQE of 5.37%

and breaked the limit of 5% of the EQE of traditional fluorescent OLEDs. The HAT-CN/NPB heterojunction units effectively reduced the driving voltage of OLEDs (2.7 V)

and the maximum EQE increased to 5.76% at the same time. Additionally

From the lg

-lg

curves and the impedance spectrum analysis

the hole-only devices with HAT-CN improved the hole mobility and reduced the impedance of the devices. This study shows that TADF materials have great potential in enhancing the optoelectronic performance of OLEDs.

关键词

Keywords

references

AHN D H,MOON J S,KIM S W,et al.. Effect of various host characteristics on blue thermally activated delayed fluorescent devices[J]. Org. Electron., 2018,59:39-44.

SIDDIQUI Q T,AWASTHIA A,BHUI P,et al.. Thermally activated delayed fluorescence (green) in undoped film and exciplex emission (blue) in acridone-carbazole derivatives for OLEDs[J]. J. Phys. Chem. C, 2019,123(2):1003-1014.

CHEN J X,WANG K,ZHENG C J,et al.. Red organic light-emitting diode with external quantum efficiency beyond 20% based on a novel thermally activated delayed fluorescence emitter[J]. Adv. Sci., 2018,5(9):1800436-1-7.

NIKOLAENKO A E,CASS M,BOURCET F,et al.. Thermally activated delayed fluorescence in polymers:a new route toward highly efficient solution processable OLEDs[J]. Adv. Mater., 2015,27(44):7236-7240.

LEE S Y,YASUDA T,KOMIYAMA H,et al.. Thermally activated delayed fluorescence polymers for efficient solution-processed organic light-emitting diodes[J]. Adv. Mater., 2016,28(21):4019-4024.

ZHU Y H,ZHANG Y W,YAO B,et al.. Synthesis and electroluminescence of a conjugated polymer with thermally activated delayed fluorescence[J]. Macromolecules, 2016,49(11):4373-4377.

BELL B M,CLARK T P,DE VRIES T A,et al.. Boron-based TADF emitters with improved OLED device efficiency roll-off and long lifetime[J]. Dyes Pigm., 2017,141:83-92.

ZHANG T Y,ZHAO B,CHU B,et al.. Efficient exciplex emission from intramolecular charge transfer material[J]. Org. Electron., 2015,25:6-11.

LEE S Y,YASUDA T,NOMURA H,et al.. High-efficiency organic light-emitting diodes utilizing thermally activated delayed fluorescence from triazine-based donor-acceptor hybrid molecules[J]. Appl. Phys. Lett., 2012,101(9):093306-1-4.

GOUSHI K,YOSHIDA K,SATO K,et al.. Organic light-emitting diodes employing efficient reverse intersystem crossing for triplet-to-singlet state conversion[J]. Nat. Photon., 2012,6(4):253-258.

LIU N,SHI W X,ZHOU Y M,et al.. Impact of dopant aggregation on the EL of blue fluorescent host-dopant emitters[J]. IEEE Electron Device Lett., 2019,40(5):750-753.

CHEN S,ZENG P J,WANG W G,et al.. Naphthalimide-arylamine derivatives with aggregation induced delayed fluorescence for realizing efficient green to red electroluminescence[J]. J. Mater. Chem. C, 2019,7:2886-2897.

ZHANG Y G,ZHANG D D,TSUBOI T,et al.. Simultaneous enhancement of efficiency and stability of OLEDs with thermally activated delayed fluorescence materials by modifying carbazoles with peripheral groups[J]. Sci. China Chem., 2019,62(3):393-402.

LIU T T,LI S H,WANG W J,et al.. Reduced optically pumped amplified spontaneous emission threshold of BUBD-1 thin films by thermally activated delayed fluorescent materials[J]. J. Lumin., 2019,212:76-82.

ZHANG D D,DUAN L,LI C,et al.. High-efficiency fluorescent organic light-emitting devices using sensitizing hosts with a small singlet-triplet exchange energy[J]. Adv. Mater., 2014,26(29):5050-5055.

ZHONG Z Y,ZHONG Y X,LIU C,et al.. Study on the surface wetting properties of treated indium-tin-oxide anodes for polymer electroluminescent devices[J]. Phys. Stat. Solidi A, 2003,198(1):197-203.

MAYR C,TANEDA M,ADACHI C,et al.. Different orientation of the transition dipole moments of two similar Pt(Ⅱ) complexes and their potential for high efficiency organic light-emitting diodes[J]. Org. Electron., 2014,15(11):3031-3037.

MAYR C,SCHMIDT T D,BRTTINGW. High-efficiency fluorescent organic light-emitting diodes enabled by triplet-triplet annihilation and horizontal emitter orientation[J]. Appl. Phys. Lett., 2014,105(18):183304.

WANG Z J,ZHAO J,ZHOU C,et al.. Enhancement of Frster energy transfer from thermally activated delayed fluorophores layer to ultrathin phosphor layer for high color stability in non-doped hybrid white organic light-emitting devices[J]. Chin. Phys. B, 2017,26(4):047302-1-7.

ZHAO J,WANG Z J,WANG R,et al.. Hybrid white organic light-emitting devices consisting of a non-doped thermally activated delayed fluorescent emitter and an ultrathin phosphorescent emitter[J]. J. Lumin., 2017,184:287-292.

SUN H D,GUO Q X,YANG D Z,et al.. High efficiency tandem organic light emitting diode using an organic heterojunction as the charge generation layer:an investigation into the charge generation model and device performance[J]. ACS Photon., 2015,2(2):271-279.

GUO Q X,DAI Y F,SUN Q,et al.. Properties of highly efficient charge generation and transport of multialternating organic heterojunctions and its application in organic light-emitting diodes[J]. Adv. Electron. Mater., 2018,4(9):1800177-1-11.

AZIMI H,SENES A,SCHARBER M C,et al.. Charge transport and recombination in low-bandgap bulk heterojunction solar cell using bis-adduct fullerene[J]. Adv. Energy Mater., 2011,1(6):1162-1168.

MIHAILETCHI V D,VAN DUREN J K J,BLOM P W M,et al.. Electron transport in a methanofullerene[J]. Adv. Funct. Mater., 2003,13(1):43-46.

GUO Y Y,WANG W J,LI S H,et al.. Improved efficiency of organic light emitting devices using graphene oxide with optimized thickness as hole injection layer[J]. Solid-State Electron., 2019,153:46-51.

Views

304

下载量

CSCD

Alert me when the article has been cited

提交

Tools

Publicity Resources

No data

Related Author

No data

Related Institution

No data

Address：No.3888 Dong Nanhu Road, Changchun, Jilin, China Postal code：130033
Tel：0431-86176862 Email：fgxbt@126.com
Technical support is provided by Beijing Founder electronics co., LTD 吉ICP备11002662号-17 京公网安备11010802024621
It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.

⁰