- 标题
- 摘要
- 关键词
- 实验方案
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24.2: <i>Invited Paper:</i> High‐resolution OLED Display Fabricated by Electrohydrodynamic Printing Method
摘要： A high resolution OLED display was fabricated by using electrohydrodynamic printing method. The printed inks were poly(dibenzothiophene-S, S-dioxide-co-9,9-dioctyl-2,7-fluorene) (PPF-SO). Both of the printer operation voltage and the solvent properties dominated the ink’s printability and printing stability. Line widths of the printed polymers could be controlled. A mono-color display with resolution over 2000 PPI was realized. The electrohydrodynamic printing method for fabrication of OLED displays will be discussed in the presentation.
关键词： High resolution,Organic light-emitting diodes,Solution process,Electrohydrodynamic printing
更新于2025-09-19 17:13:59
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Structural isomers of 9-(pyridin-2-yl)-9H-carbazole in combination with 9a?2H-9,3':6a?2,9a?3-tercarbazole and their application to high efficiency solution processed green TADF OLEDs
摘要： Two host materials, CzPy2TCz and CzPy3TCz, were designed as structural isomers and synthesized to achieve high efficiency thermally activated delayed fluorescence-organic light emitting diodes (TADF-OLEDs). The design strategy involved introducing a pyridine group into the core structure as an electron-withdrawing unit and varying the substitution position of tercarbazole (TCz). To realize green TADF-OLED, the two host materials synthesized in this study have excellent thermal stability and high excited triplet energy (T1 ? 2.95–2.98 eV). The maximum external quantum efficiency and current efficiency values for CzPy2TCz were 23.81% and 80.2 cd/A, respectively and the respective values for CzPy3TCz were 20.27% and 70.1 cd/A, respectively. Structural isomers with carbazole (Cz) and TCz units at the 2,6-position of the pyridine core effectuate better device performance. Consequently, we found that the host materials introduced in this study play an important role in implementing high performing solution-processed green TADF-OLED.
关键词： Thermally activated delayed fluorescence,Organic light-emitting diode,Tercarbazole,Pyridine,Host material,Solution process
更新于2025-09-19 17:13:59
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Efficient flexible Mo foil-based Cu2ZnSn(S, Se)4 solar cells from In-doping technique
摘要： Cation substitution has an important impact on the power conversion efficiency (PCE) of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Herein, a significant PCE enhancement of flexible indium-doped CZTSSe solar cells has been achieved by partially substituting Sn4+ with In3+. Systematic measurements indicate that In doping in CZTSSe film effectively improves the crystallinity and carrier concentration of the absorber layer. Meanwhile, the treatment reduces interface recombination and band tailing by passivating deep defects and increases the open-circuit voltage (Voc) of the solar cells. By physical analysis, the key parameters for the solar cell diode such as A, J0, Rs and Rsh are significantly improved after In-doping, indicating better PN junction quality. Under the optimal In-doping (x ? In/(Sn t In) ? 9%), the flexible Cu2ZnSn1-xInx(S,Se)4 solar cell has been successfully obtained with the best efficiency of 7.19% and the Voc enhancement of 62 mV due to reduced Voc deficit and band tailing.
关键词： Solution process,In dopant,Mo foil,Flexible CZTSSe solar cells
更新于2025-09-19 17:13:59
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High Efficiency Solution-Processed Organic Light-Emitting Diodes with Tetradentate Platinum(II) Emitters
摘要： The realization of high efficiency solution-processed organic light-emitting diodes (OLEDs) by using phosphorescent tetradentate Pt(II) emitters and bipolar organic hosts is demonstrated in this work. To investigate the effect of organic host on the platinum dopant, the performances of solution-processed Pt-OLEDs with various combination between four tetradentate Pt(II) emitters, including two newly developed tetra-Pt-S2 and tetra-Pt-S3, and three bipolar organic hosts m-TPAPy, o-TPAPy, and o-CzPy, have been analyzed and compared. Among the tetradentate Pt(II) complexes studied in this work, tetra-Pt-S3 exhibited the best electroluminescent performance attributable to its bulky molecular scaffold structure, high emission quantum yield, and good solubility in common organic solvents. High external quantum efficiencies (EQEs) of up to 22.4% were achieved in the solution-processed OLED with tetra-Pt-S3 emitter and m-TPAPy host at the dopant concentration of 4 wt%. At a high luminance of 1000 cd m-2, the EQE of this device decreased slightly to 21.0%.
关键词： high efficiency,platinum complexes,organic light-emitting diodes,solution-process,bipolar organic host
更新于2025-09-16 10:30:52
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Blocking exciton-quenching pathways in host and guest interfaces for high performance solution-processed TADF OLEDs with external quantum efficiency approaching 25%
摘要： Although doping system can effectively reduce the concentration quenching of thermally activated delayed fluorescence emitter, the inevitable collision between host and guest may be other energy leakage pathways, which are usually ignored in the previous studies. Here, a new encapsulated molecule Cz-4CzIPN with TADF emissive core and steric shield is conveniently synthesized and fully characterized. The TADF property ensures the efficient triplet exciton utilization, while the encapsulated feature endows the adjacent molecules a big steric bulk to reduce exciton quenching. By using the encapsulated TADF materials as both host and guest, solution-processed TADF OLEDs achieved the maximum external quantum efficiency (EQE) as high as 24.3%, which is among the best results for solution-processed TADF OLEDs reported so far. However, removing any protection of host or guest, the device efficiency will be accordingly reduced. Particularly, when the host and guest are both unencapsulated, the device can only exhibits the EQEmax of 8.0%, which indicates the existence of severe exciton quenching process. This research demonstrates the molecular interface engineering is a promising strategy for blocking the exciton quenching pathways of the solution-processed doping system by suppressing the intermolecular interaction.
关键词： TADF,host-guest interfaces,solution-process,organic light emitting diodes technology
更新于2025-09-16 10:30:52
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P3HT-based visible-light organic photodetectors using PEI/PAA multilayers as a p-type buffer layer
摘要： A low leakage current is critical for achieving organic photodetectors (OPDs) with high detectivity. The insertion of buffer layers is an effective approach for reducing the reverse-biased leakage current. In this study, polyelectrolyte multilayers comprising polyethyleneimine (PEI) and polyacrylic acid (PAA) were introduced by a spin-assisted layer-by-layer technique into an OPD as a p-type buffer layer. Although PEI/PAA multilayers are insulators, when used as a buffer layer in our device, they suppressed the leakage current and also provided a high photocurrent due to the light-assisted tunneling effect. The prepared device configuration was ITO/(PEI/PAA)2/P3HT:PC60BM/Yb/Al. The performances of the OPDs were investigated by measuring the current–voltage characteristics, external quantum efficiency, and transient photocurrent. In addition, the operating mechanism of the OPDs was confirmed by impedance analysis. The device comprising (PEI/PAA)2 showed a specific detectivity of 3.11 × 1012 Jones and a bandwidth of 103.2 kHz at ?1 V and 525 nm. This performance is a numerical value that can be used in devices such as a line scan camera. In addition, because this device is fabricated by a low-temperature solution process, flexible and large-area substrates can be used.
关键词： light-assisted tunneling effect,organic photodetectors,PEI/PAA multilayers,p-type buffer layer,low-temperature solution process
更新于2025-09-16 10:30:52
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Preparation of highly transparent conductive aluminum-doped zinc oxide thin films using a low-temperature aqueous solution process for thin-film solar cells applications
摘要： In this work, we developed a facile route to fabricate highly transparent conductive AZO thin films by using an aqueous solution process followed by an ultraviolet (UV) exposure technique at an annealing temperature as low as 200 °C, where the aluminum citrate complex was used as the Al doping source. Various of deposition parameters in the AZO thin films fabrication process were studied and optimized. The mechanisms on UV exposure and heat treatment to the conductivity improvement and conductivity stability of the AZO films were analysed. Results showed that the AZO thin films under the best parameters conditions demonstrated an optical transmittance higher than 85% in the visible spectra region and a lowest electrical resistivity of 4.8 × 10?3 Ω cm, while exhibited densely oriented columnar grains and uniform surface morphology as well as uniform composition distribution. The UV exposure could remove carbon species from the surface of the AZO thin films to reduce oxygen-related defects and release free carriers at the boundaries and interfaces, thereby improving the conductivity of the AZO thin films. The simultaneous treatment of the AZO thin film by ultraviolet exposure and heat treatment could remove carbon species at a deeper thickness, thereby improving the conductive stability of the AZO thin films. Kesterite Cu2ZnSnS4 thin film solar cells incorporating the optimal AZO thin films as top electrodes demonstrated a best power conversion efficiency (PCE) of 7.15%, which was comparable to the PCE value obtained by using the sputtering deposited AZO thin films as top electrodes.
关键词： AZO thin films,Aqueous solution process,Photoelectric properties,Ultraviolet exposure,Cu2ZnSnS4 thin film solar cells
更新于2025-09-16 10:30:52
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Low temperature ZnO/TiOx electron-transport layer processed from aqueous solution for highly efficient and stable planar perovskite solar cells
摘要： Owing to the low temperature processability and high charge carrier mobility, ZnO has been successfully employed in perovskite solar cells (PSCs) to act as the electron transport layer. Even so, because of the poor ZnO/perovskite interface chemical stability, achieving highly ef?cient and stable PSCs is still challenging the researchers. Therefore, the optimization of ZnO/perovskite interface by proper surface passivation has been developed for highly ef?cient PSCs. In this work, an environmentally friendly low-temperature aqueous solution-processed TiOx was applied on the aqueous solution-processed ZnO surface to promote the ZnO/perovskite interface stabilization and the interface charge recombination reduction. High performance PSCs with over 19% ef?ciency and relatively good stability were ?nally obtained. This low temperature aqueous solution-processed ZnO/TiOx route is simple and scalable, and facilities the future commercialization of perovskite based photovoltaic technology. Meanwhile, it is also compatible with the ?exible energy devices.
关键词： Electron transport layer,High performance,Aqueous solution-process,Perovskite solar cells,ZnO/TiOx layer
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK) - Kyoto, Japan (2019.11.14-2019.11.15)] 2019 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK) - Invited: Polymer Light-Emitting Devices with Selectively Transparent Photonic Crystals Consisting of Printed Inorganic/Organic Hybrid Dielectric Films
摘要： Selectively transparent photonic crystals consisting of printed inorganic/organic hybrid dielectric films based on inorganic copper(I) thiocyanate can be produced to exhibit intense Bragg peaks over their stop band in the visible region. This work exhibits a unique approach to achieve the improvement of color purity and the strong directed emission pattern for polymer light-emitting diodes and AC-driven electroluminescent devices with printed inorganic/organic hybrid dielectric mirrors, which will be important for all-printed microlight sources.
关键词： photonic crystal,dielectric film,distributed Bragg reflector,inorganic/organic hybrid film,polymer light-emitting device,solution process
更新于2025-09-16 10:30:52
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Cu2ZnSnS4 as an efficient hole transporting material for low temperature paintable carbon electrode based perovskite solar cells
摘要： Introducing a solution processed hole transporting layer into the low temperature paintable carbon electrode based perovskite solar cells is highly desirable to further enhance their power conversion efficiencies. At the same time, this low cost method is compatible with roll-to-roll mass production. Here, we have demonstrated that Cu2ZnSnS4 (CZTS) nanoparticles can be a potential hole transporting layer for low temperature paintable carbon electrode based perovskite solar cells. Under optimized conditions, perovskite solar cells with a CZTS hole transporting layer exhibit an average power conversion efficiency of 12.53%, which is enhanced by ~50% compared with perovskite solar cell without a CZTS hole transporting layer. At the same time, perovskite solar cells with CZTS hole transporting layer demonstrate negligible hysteresis and excellent long time stability.
关键词： Inorganic hole transporting layer,Carbon electrode,Cu2ZnSnS4,Solution process,Perovskite solar cell
更新于2025-09-16 10:30:52