COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2023
·
IF 8.7
Xinzuo Huang,Rongxiang Hu,Fenghua Zhang,Yanju Liu,Jinsong Leng
An innovative process for producing flexible transparent graphene electrodes has been proposed. The electrochemically polished copper-foil was used as the metal substrate to prepare high-quality monolayer graphene. Monolayer graphene was transferred from copper-foil to transparent shape memory polyimide (TSMPI) intactly by novel flow-casting transfer technology, and the smart, ultra-clean and smooth flexible graphene electrode (pG@TSMPI) was fabricated. The light transmittance of pG@TSMPI at 550 nm is 86%, the average sheet resistance is 310 Ω/sq, and the surface roughness (Ra) is 18 nm. Smart white OLED was manufactured using pG@TSMPI as transparent anode, and its luminescence performance was comparable to that of ITO-based device. Depending on the shape memory effect of TSMPI substrate, the smart OLED has the superiorities of variable stiffness and reconfigurable shape, which can transform from 2D structure into complex 3D structure.
研究领域:
材料科学
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光电技术
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产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2024
·
IF 2.7
Cangyu Wang,Xiaoge Song,Sinyeong Jung,Wansi Li,Maggie Ng,Season Si Chen,Man-Chung Tang
Recent research on anthracene-based hydrocarbon (PNA) as the emissive layer host found that deuteration mediated the formation of these adduct species, presumably quenchers, and thus improved the device lifetime. Meanwhile, studies on deuterium in PNA host materials with stepwise deuteration are scarce. In this work, we report a systematic study of isotopic effects through independent deuteration of the phenyl or/and the dibenzofuran unit on a series of PNA materials polyaromatic dibenzofuran ( PAF , PAF- d 5 , PAF- d 7 and PAF- d 12 ). We fabricated fluorescent OLED based on this triplet-triplet up-conversion active host materials for conventional MR-TADF emitter. A short-lived excited delayed lifetime of less than 2 μs has been observed in their electroluminescence decay studies. In addition, LT 80 of up to 12.7 h has been observed in PAF- d 12 at the brightness of 1000 cd m −2 , corresponding to a 4-fold enhancement of OLED stability compared to the non-deuterated counterpart. We hope the current research can provide insights for further device improvement.
研究领域:
材料科学
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有机电子学
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产品关联
DOI
高影响因子
SURFACE REVIEW AND LETTERS
·
2019
·
IF 0.748
PING LIU,JIANGHAO WANG,JIE CHENG,LIMING LIU,HONGHANG WANG,BAOQING ZENG,FENG CHI
A flexible organic light-emitting device (OLED) was produced using copper nanowire (CuNW) film as anode and Graphene oxide (GO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film as anode buffer layer. Compared with other transparent conductive films (TCFs), CuNWs are low cost, easy to fabricate, and compatible with flexible substrates over a large area. Due to these advantages, CuNWs are showing greater and greater promise for the next generation of TCF. Modified by PEDOT:PSS, the conductivity and work function of the CuNW film can be dramatically enhanced. However, PEDOT:PSS is highly acidic and easy to corrode the CuNW film, which will reduce maximum luminous brightness and current efficiency of the OLED. In this paper, GO/PEDOT:PSS was used as anode buffer layer to modify the CuNW anode and the composite transparent electrode exhibited excellent optoelectrical properties. The driving voltage of the OLED with CuNW/PEDOT:PSS is 6.2 V, and the maximum luminous brightness is 2737.2 cd/m 2 . The driving voltage of the OLED with CuNW/GO/PEDOT:PSS anode was reduced to 5.1 V, and the maximum luminous brightness was improved to 3007.4 cd/m 2 .
研究领域:
材料科学
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光电技术
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Huimin Xu,Xuan Zhao,Guihua Yang,Xingxiang Ji,Xingye Zhang,Lijuan Li,Bangxue Wu,Xinhua Ouyang,Yonghao Ni,Lihui Chen,Hui-Chao Hu
Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonic acid) (PEDOT:PSS) emerges as a promising transparent conducting electrode to replace indium tin oxide (ITO) in the field of optoelectronic devices. It is a pending issue that how to achieve high-conductivity PEDOT:PSS to meet the requirement as device electrode. In this work, two biomass-derived modifiers of PEDOT:PSS, i.e. , protocatechuic acid (PA) and gentianic acid (GtA), were investigated. The resultant conductivity was respectively estimated as 2022 S/cm (PA-treated) and 2270 S/cm (GtA-treated), in comparison with that of the ordinarily prepared film (∼0.9 S/cm). By analyzing the PEDOT/PSS ratio, phase morphology, as well as benzenoid/quinoid conformation, crystalline structure, the mechanism on conductivity enhancement was systematically elucidated. Based on the density functional theory, the synergistic effect of carboxy and phenol groups was verified as the origin of excellent doping-efficiency of these two biomass-derived modifiers. What is more, an ITO-free OLED device was successfully fabricated, where the PA or GtA-treated PEDOT:PSS was employed as transparent conducting electrode. Surprisingly, a remarkable improvement with regard to device performance was observed, in spite of the not good enough conductivity relative to ITO . Using the PA/GtA-modified electrodes, the external quantum efficiency (EQE), current efficiency, and power efficiency of OLED devices is elevated by 50–300% at the brightness of 100 cd/m 2 for electronic display application. To reveal the underlying mechanism, the energy levels and the light extraction were examined and then ascribed to the paradox. The findings present a possible strategy to construct high-efficiency OLEDs relying on organic transparent electrodes and a promising application of biomass-derived chemicals.
研究领域:
材料科学
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有机电子学
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能源与环境科学
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产品关联
DOI
高影响因子
Small Methods
·
2022
·Vol. 6
·期 4
·2101509
·
IF 15.367
Xiaojie Zhou,Yichen Cai,Mingsheng Xu,Jianping Li,Chenxu Sheng,Qiuyi Zhang,Xinxia Qiu,Wenchong Wang,Shisheng Xiong,Chunxiao Cong,Zhi-Jun Qiu,Ran Liu,Laigui Hu
The emergence of near-eye displays, such as head-mounted displays, is triggering a requirement for highly enhanced display resolution. High-resolution micro-displays with micro-organic light-emitting diodes (micro-OLEDs) can be a preferential candidate, owing to the mature industrialization of OLEDs along with the advantages of flexibility, light weight, and ease of processing. However, micro-OLEDs with pixel sizes down to micrometers are difficult to be achieved using conventional techniques such as fine metal mask evaporation and lithography. Here, a solution-processing approach to pattern organic semiconductors (OSCs) for micro-OLED arrays with the assistance of templated dewetting is demonstrated. Solvents containing organic functional materials are dewetted on the surface with hydrophobic/hydrophilic patterns to form ordered droplet arrays using dip-coating. Subsequently, patterned OSC films are produced by effectively controlling solvent evaporation. Micro-OLED arrays with a pixel size down to 1 µm are successfully fabricated by further deposition of emitting/electron transport layers and top electrodes. This approach can open an avenue for low-cost manufacturing of flexible and high-resolution micro-displays.
研究领域:
材料科学
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显示技术
·
有机电子学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2022
·
IF 4.855
Yuan-Yuan Liu,Jian-Hua Cao,Ying Wang,Shao-Gang Shen,Wei-Hua Liang,Da-Yong Wu
In this study, we intend to solve the problem of the low glass transition temperature (Tg) and the high coefficient of thermal expansion (CTE) that colorless polyimide (PI) films always exhibit. First, we copolymerized 2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diamine (TFDB) with 4,4′-(hexafluoroisopropene) diphthalic anhydride (6FDA) and p-phthaloyl chloride (TPC) and obtained a series of transparent and colorless films (PAI-10). These PAI films showed a high Tg of 346–362 °C and a low CTE of 25.2–62.9 ppm/K, which were better than those of PI6FDA-TFDB. Subsequently, three rigid diamines, p-phenylenediamine (p-PDA), 5-amino-2-(4-aminophenyl)benzoxazole (DAPBO) and 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI), were used to replace 10% of the TFDB (PAI-9P-5, PAI-9O-5, and PAI-9I-5, respectively) to investigate the effect of the rigid structure on the thermal and optical properties. The results showed that rigid structures can greatly improve the thermal properties but impair transparency to some extent. Among these, PAI-9O-5 possessed the best performance with T430 of 81.9%, Tg of 364 °C, and CTE of 19.8 ppm/K. Furthermore, we fabricated an organic light-emitting diode (OLED) with PAI-9O-5 as the substrate. The flexible and bendable OLED@PAI-9O-5 showed typical green emission at 520 nm, a turn-on voltage of 2.9 V, a luminance of 1000 cd/m2 at 5 V, a current efficiency (CE) of 2.53 cd/A, and an external quantum efficiency (EQE) of 0.81%, which were comparable to those of devices fabricated on conventional glass substrates.
研究领域:
材料科学
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高分子化学
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光电学
·
柔性电子学
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产品关联
DOI
高影响因子
Optoelectronics Letters
·
2018
·Vol. 14
·期 4
·262-266
·
IF 0
Hu Jun-tao,Ye Kang-li,Huang Yang,Wang Peng,Xu Kai,Wang Xiang-hua
In this paper, p-chlorophenylacetic acid and p-fluorophenylacetic acid were applied to modify the indium tin oxide (ITO) electrodes. The surface work functions of unmodified ITO, p-chlorophenylacetic acid modified ITO (Cl-ITO) and p-fluorophenylacetic acid modified ITO (F-ITO) are 5.0 eV, 5.26 eV and 5.14 eV, respectively, and the water contact angles are 7.3°, 59.1° and 46.5°, respectively. The increase of the work function makes the hole injection ability of the devices improved, which is proved by the hole transport devices. The self-assembly (SAM) layers transfer hydrophilic ITO to hydrophobic ITO, which makes ITO more compatible with the hydrophobic organic layers, making the organic film more stable during the operation. After modification, the organic light emitting diodes (OLEDs), SAM-modified ITO/NPB/Alq3/LiF/Al, with better performance and stability were fabricated. Especially, the OLED with Cl-ITO (Cl-OLED) has a maximum luminance of 22 428 cd/m 2 (improved by 32.9%) and a half-lifetime of 46 h. Our results suggest that employing organic acids to modify ITO surface can enhance the stability and the luminescent properties of OLED devices.
研究领域:
材料科学
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光电功能材料
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表面化学
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有机电子学
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器件物理
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薄膜稳定性
✓ 已验证
DOI
ACS Photonics
·
2025
·
IF 6.7
Qiuyi Zhang,Qi Huang,Zikai Zhu,Dacheng Xia,Chenxu Sheng,Shoaib Awan,Ziyang Song,Fengxian Xie,Chunxiao Cong,Zhi-Jun Qiu,Laigui Hu,Ran Liu
Although organic light-emitting diodes (OLEDs) have been widely employed in displays and flexible electronics, the implementation of micro-OLED arrays still remains a challenge due to the limitations of the mainstream fine metal mask (FMM) technology. Pixel sizes below 30 μm are typically hard to achieve in order to match the requirement (i.e., sub10 μm) of the emerging near-eye displays mainly due to the so-called “screen-door effect”. Conventional lithography used for high-resolution inorganic micro patterns cannot be directly applied owing to the instability of organic materials. Furthermore, damage-free techniques such as inkjet printing also encounter resolution limitations. Self-assembled monolayer (SAM)-assisted patterning and surface-microstructure-assisted patterning techniques, though promising, have so far only been applied to fabricate single-color micro-OLEDs. In this work, high-resolution micro-OLED arrays with dual-color emission were demonstrated using a phase-change material (PCM) or an aggregation-induced emission (AIE) material. Fabricated via the SAM-assisted patterning technique, the PCM dot array exhibits red emission in its amorphous phase and transitions to green emission upon annealing-induced crystallization. Leveraging this unique dual-color capability, micro-OLEDs with 5 μm pixels (2600 PPI) and dual-color emission were achieved after the preparation of other functional layers.
研究领域:
材料科学
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显示技术
·
光电子学
·
纳米技术
·
薄膜器件
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Jingyi Xie,Dongmei Jia,Mahmut Dirican,Yi Xia,Chunxing Li,Yi Liu,Meng Cui,Chaoyi Yan,Jiayu Wan,Hao Liu,Gang Chen,Xiangwu Zhang,Jinsong Tao
Polymer cover windows are important components of flexible OLED displays but they easily generate wrinkles because of their weak folding resistance. Increasing the polymer thickness can improve the folding resistance but it decreases the touch sensitivity. Thus, fabricating highly foldable and supersensitive polymer cover windows is still challenging. Here, by incorporating cellulose nanocrystals (CNCs) and zirconia (ZrO2) into colorless polyimide (CPI), we developed a highly foldable and supersensitive hybrid cover window. Inspired by the theory of elasticity, we added rigid CNCs into CPI to improve the elastic modulus and hence the foldability. ZrO2 was introduced to improve dielectric properties, which leads to improved touch sensitivity. After these modifications, the elastic modulus of the cover windows was increased from 1432 to 2221 MPa, whereas its dielectric constant was increased from 2.95 to 3.46 (@1 × 106 Hz), resulting in significantly enhanced foldability and sensitivity. Meanwhile, because of the nano size of CNCs and ZrO2, the hybrid cover windows exhibit excellent optical properties with the transmittance of ∼88.1%@550 nm and haze of 2.39%. With improved and balanced mechanical, dielectric, and optical properties, these hybrid cover windows overcome current cover windows’ defects and could be widely used in next-generation flexible displays.
研究领域:
材料科学
·
光学工程
·
电子工程
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产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 37
·5364-5376
·
IF 5.582
Zhenghui Yang,Haiquan Guo,Chuanqing Kang,Lianxun Gao
Three novel dianhydride monomers involving amide groups were synthesized and further polymerized with various diamines to afford a series of colorless polyimides (cPI). The resultant cPI films present outstanding optical performance, exceedingly good dimensional stability at high temperature, great film ductility and solution-processability. In particular, chemically imidized AMDA/TFDB has an ultra-low coefficient of thermal expansion value of 5.2 ppm K−A, a relatively high Tg value of 333 °C and large elongation at break of 29%, resulting from its rigid-rod backbone and the formation of hydrogen bonding (–CO⋯NH–) between adjacent molecular chains. Concurrently, it exhibits a high optical transmittance of 87% at a wavelength of 550 nm, a small haze value of 0.71 and low yellow index of 4.29 by reason that the incorporation of bulky trifluoromethyl and cyclohexyl preclude the formation of a charge transfer complex effectively. The high overall performance of the amide-containing cPI films suggests its potential application in the field of flexible OLED displays.
研究领域:
材料科学
·
显示技术
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 13
·4496-4504
·
IF 7.393
Qinghong Zheng,Huixin Li,Yiling Zheng,Yinan Li,Xi Liu,Shuangxi Nie,Xinhua Ouyang,Lihui Chen,Yonghao Ni
A cellulose-based flexible organic light-emitting diode (OLED) with enhanced stability and light extraction efficiency was prepared by using a PEDOT:PSS PH1000 transparent conductive electrode coated on regenerated cellulose film (RCF). The PH1000/RCF transparent conductive electrode exhibits extra-high bending stability as compared to the traditional ITO/RCF electrode, which can be attributed to the highly flexible nature of PH1000 and the strong interaction between PH1000 and cellulose. Finite-difference-time-domain simulations show that, due to the smaller refractive index mismatch between PH1000 and RCF, a small proportion of photons are confined in the optical waveguide. The external quantum efficiency of the PH1000/RCF OLED (3.65%) is enhanced by nearly 36.2%, as compared to the ITO/RCF OLED device (2.68%). The ITO-free cellulose-based flexible OLED with enhanced stability and external quantum efficiency would be attractive in a wide range of applications, such as flexible displays, wearable devices and so on.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Chaohua Peng,An Huang,Xinjie Ma,Jiahui Zhong,Guorong Chen,Weiang Luo,Birong Zeng,Conghui Yuan,Yiting Xu,Lizong Dai
With the rapid development of flexible OLED display technology, Poly(ethylene terephthalate) (PET) has also received extensive attention as a protective film. However, it is still a challenge to endow PET with abrasion resistance and flame retardancy while maintaining transparency and flexibility. Here, we developed an epoxy-amine curing hybrid coating based on phosphorus-containing organic amine (DPNP) and ladderlike epoxy-oligosiloxane (AEOS). The ratio of DPNP and AEOS was changed to study the effect of phosphorus and silicon content on the performance of hybrid coatings. All the coatings were transparent. The PET/AE-DP3 sample achieved the limiting oxygen index of 28 % and exhibited self-extinguishing in vertical burning test. In microscale combustion calorimeter (MCC) test, the minimum peak heat release rate was 236.4 W/g with a reduction of 29.5 %, compared with pure PET. In addition, the AE-DP3 coating could withstand the abrasion of copper mesh and cheese cotton with a pencil hardness of 8H, and showed good foldability with a bending diameter of 5 mm. At the same time, the coating exhibited satisfactory adhesion without plasma treatment and good UV resistance. These results indicated the hybrid coating overcome the inherited weakness of PET film such as poor scratch-resistance and flammability , promoting the wider application of PET.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）