- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Realizing 22.3% EQE and 7-Fold Lifetime Enhancement in QLED: via Blending Polymer TFB and Cross-linkable Small Molecule for Solvent-Resistant Hole Transport Layer
摘要： Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4'-(N-(4-butylphenyl))] (TFB) has been widely used as a hole transport layer (HTL) material in cadmium-based quantum dots light-emitting diodes (QLEDs) due to its high hole mobility. However, as the highest occupied molecular orbital (HOMO) energy level of TFB is -5.4 eV, the hole injection from TFB to quantum dots (QDs) layer is higher than 1.5 eV. Such high oxidation potential at the QD/HTL interface may seriously degrade the device lifetime. In addition, TFB is not resistant to most solvents, which limits its application in inkjet-printed QLEDs display. In this study, blended HTL consisting of TFB and cross-linkable small molecular 4,4 ′ -bis(3-vinyl-9H-carbazol-9-yl)1,1 ′ -biphenyl (CBP-V) was introduced into red QLEDs, because of the deep HOMO energy level of CBP-V (-6.2 eV). Compared with the TFB only devices, the external quantum efficiency (EQE) of devices with blended HTL improved from 15.9 % to 22.3 % without the increase of turn-on voltage for spin-coating fabricated device. Furthermore, the blended HTL prolonged the T90 and T70 lifetime from 5.4 h and 31.1 h to 39.4 h and 148.9 h, respectively. These enhancements in lifetime are attributed to the low hole-injection barrier at HTL/QD interface and high thermal stability of blended HTL after crosslinking. Moreover, the crosslinked blended HTL showed excellent solvent resistance after cross-linking and the EQE of the inkjet-printed red QLEDs reached 16.9 %.
关键词： charge balance,quantum dots light-emitting diodes,blended HTL,solvent resistance,inkjet printing
更新于2025-09-23 15:19:57
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Inkjet-printed silver films on textiles for wearable electronics applications
摘要： This paper presents the fabrication of an inkjet-printed silver film on various textiles for wearable electronics applications. Screen printing an interface layer (Fabink-UV-IF1) on various textiles was required in order to fill the fabric grid and realize a smooth surface for subsequent inkjet-printed layers. The surface of the interface layer was treated by hard-baking to obtain the optimal surface wettability for inkjet printing. The surface morphologies and electrical properties at different inkjet printing conditions such as droplet spacing and number of passes were analyzed. The dynamic bending of the silver film was observed, considering the requirements for wearable applications. After developing the process of the silver film on textiles, the relative permittivity and loss tangent of the four textiles (T/C fabric, pure cotton, nylon, and cleanroom wiper) with interface layer were found, and the values were close. In addition, the electrical properties before and after water washing were nearly unchanged. The results indicate that the interface layer dominates the electrical properties of various textiles. The technology of inkjet-printed silver film on various textiles provides more freedom for achieving high resolution and rapid manufacturing for wearable electronics.
关键词： inkjet printing,Screen printing,textiles,wearable electronics
更新于2025-09-19 17:15:36
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Fluorescent patterns by Selective Grafting of a Telechelic Polymer
摘要： The preparation of patterned ultrathin films (sub-10 nm) composed of end-anchored fluorescently-labeled poly(methyl methacrylate) (PMMA) is presented. Telechelic PMMA was synthesized utilizing activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and consecutively end-functionalized with alkynylated fluorescein by Cu-catalyzed azide-alkyne cycloaddition (CuAAC) 'click' chemistry. The polymers were grafted via the α-carboxyl groups to silica or glass substrates pre-treated with (3-aminopropyl)triethoxysilane (APTES). Patterned surfaces were prepared by inkjet printing of APTES onto glass substrates and selectively grafted with fluorescently end-labeled PMMA to obtain emissive arrays on the surface.
关键词： ATRP,inkjet printing,click chemistry,grafting to,polymer brushes
更新于2025-09-19 17:15:36
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Comparison of spin-on-glass and WO <sub/>3</sub> as an insulating layer for printed resistive memory devices
摘要： Resistive Random Access Memory (ReRAM) is a highly promising technology for various future memory applications. In this work, spin-on-glass (SOG) and WO3 nanoparticles are used as an insulating layer for completely inkjet-printed ReRAM cells. The direct comparison shows that the di?erence in switching parameters can be used to serve di?erent device requirements for various applications. While local ?lament formation with conductive atomic force microscopy con?rms the same switching mechanism for both compounds, the current–voltage characteristics di?er from each other. SOG as excellent insulator shows an OFF resistance in the range of GΩ and is therefore highly suitable for multi-bit data storage to increase memory density. ReRAM cells with WO3 face larger leakage currents and show a low degree of multi-bit data storage. However, WO3 can be used to fabricate completely sinter-free memory devices for applications which do not allow high temperatures in the fabrication process.
关键词： spin-on-glass,?exible electronics,printed electronics,organic electronics,inkjet printing,ReRAM
更新于2025-09-19 17:15:36
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Fully printed organic solar cells – a review of techniques, challenges and their solutions
摘要： The emergence of solar cells on flexible and bendable substrates has made the printing process a ubiquitous tool for the fabrication of these devices. The various printing techniques available now such as inkjet, screen and flexography offer cost-effectiveness, user-friendliness and suitability for mass production. While downscaling the fill factor and efficiency of organic solar cells. A multilayered structure, the combination of different printing techniques avails the variety of thickness and resolution required for each layer in the production of an organic solar cell. In this review article, we discuss the suitability of the inkjet and screen printing processes to produce organic solar cells. We also discuss various challenges involved in the fabrication of organic solar cells using these two techniques and the possible solutions for the same. We also provide an analogy that both processes share. Further, we consider future possibilities of combining these printing technologies to produce organic solar cells to improve device performance.
关键词： Screen printing,Organic solar cells,Inkjet printing
更新于2025-09-19 17:13:59
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24.3: <i>Invited Paper:</i> Printed Electrodes for All‐Solution‐Processed Inverted‐Structure OLEDs
摘要： A key enabling technology for all-printed organic light-emitting diodes is printing electrodes that can be used for anodes or cathodes for conventional or inverted device structures. In both device structures, the first bottom electrodes, which are either transparent or opaque depending on the device structure, are typically printed while the last top electrodes have been deposited by using a vacuum-based evaporation process because when the last top electrodes are fabricated by using a solution-based process, under organic layers are easily damaged during the fabrication process. Although so-called transfer printing process has been often reported for organic devices such as organic solar cells, it has been rarely applied for OLEDs. In addition, no fine patterning has been adopted in such printing processes. As part of our efforts towards all-printed OLEDs, inkjet-printed and/or transfer-printed, finely-patterned PEDOT:PSS electrodes have been investigated in our lab and most recent achievement will be reported in detail. In order to implement all-solution-processed OLEDs, we also studied the inverted-structure OLEDs, which showed comparable results to the conventional structure OLEDs with the vacuum-based deposited electrodes.
关键词： inverted structure,Organic light-emitting diode,OLED,PLED,inkjet-printing,transfer-printing,polymer light-emitting diode
更新于2025-09-19 17:13:59
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Inkjet printing multilayer OLEDs with high efficiency based on the blurred interface
摘要： Inkjet printing technology is considered to be the next generation manufacturing method for organic light-emitting diodes (OLEDs) production because of its simplicity and low cost. However, the dissolution at interfaces in printing process is still one of the great challenges that limits its progress. The present work utilized the dissolution phenomenon innovatively to generate blurred interface during inkjet printing of multi-layer OLEDs, where TAPC and TAPC:TPBi:Ir-complexes were employed as hole transport layer (HTL) and emitting layer (EML) and both of them were dissolvable in butyl benzoate to form the HTL and EML inks. When they were printed sequentially, a blurred interface between HTL and EML was formed because the dissolution phenomenon, which facilitated the exciton formation and charge balance in EML and improved the device performance. With this blurred interface, the maximum current efficiency of 9.8 cd A-1, the maximum power efficiency of 5.0 lm W-1, and the maximum external quantum efficiency of 3.0% were achieved in (fpbt)2Ir(acac) based OLEDs. In contrast, they were only 7.4 cd A-1, 3.9 lm W-1 and 2.2% in devices having a clear interface between HTL and EML.
关键词： organic light emitting diodes (OLEDs),blurred interface,inkjet printing
更新于2025-09-19 17:13:59
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Facile synthesis and color conversion of Cu-doped ZnSe quantum dots in an aqueous solution
摘要： A facile growth-doping method in aqueous solution has been developed to synthesize Cu-doped ZnSe (ZnSe:Cu) QDs by using thioglycolic acid (TGA) as a stabilizer. The effects of the Cu doping concentration, reaction temperature and pH value on the synthesis of ZnSe:Cu QDs were investigated systematically. The as-synthesized ZnSe:Cu QDs with an excellent green emission still belong to a cubic zinc blende crystalline structure, and the average particle size is approximately 3.0 nm. The photoluminescent quantum yield (PLQY) is as high as 20%, and the exciton radiative lifetime is approximately 113.8 ns. Moreover, the patterned ZnSe:Cu QDs thin films have been successfully fabricated by using an inkjet printing method to verify the ability of the potential application to the color conversion. With the assistance of 5.5 pair distributed bragg reflector (DBR) structures, the color coordinate of the ZnSe:Cu QDs thin film excited by the blue LEDs is located at (0.2182, 0.4352) and the intensity of PL peak located at 513 nm reaches to be 45.1%. In addition, the PLQY of color conversion-based ZnSe:Cu QDs thin film is approximately 9.64%. Based on these results, ZnSe:Cu QDs are potentially useful for the fabrication of optoelectronic devices, especially QDs photoluminescence and electroluminescence.
关键词： color conversion,Cu-doped ZnSe QDs,photoluminescent quantum yield,inkjet printing,aqueous solution
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Las Vegas, NV, USA (2019.5.28-2019.5.31)] 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Fully Additively Manufactured Tunable Active Frequency Selective Surfaces with Integrated On-package Solar Cells for Smart Packaging Applications
摘要： A ?rst-of-its-kind fully inkjet-printed electronically tunable active ?exible frequency selective surface (FSS) using varactors with integrated on-package solar cells is presented in this paper. Each varactor is biased by a dedicated on-package inkjet-printed solar cell using a low-temperature fabrication process. The solar cell changes its output voltage with variation in light intensities that eventually leads to a change in capacitance of the varactor and overall frequency response of the FSS. The proposed design eliminates the use of labor intensive biasing network, bulky power supply and micro-controllers to tune the FSS frequency response. These structures presents an autonomous, ultra low cost on-package RF shielding mechanism for next-generation of system-on-chip packaging applications that can be tuned on-demand at different frequency bands by simple variation of incident light intensities. Thus making them useful for a wide range of terrestrial, outer-space and EMI shielding applications.
关键词： Additive manufacturing,tunable FSS,solar cells,Frequency selective surfaces,varactors,tunable RF structures,inkjet printing
更新于2025-09-16 10:30:52
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Effect of using ink containing polyacrylate and silicone surfactant on the inkjet printing of quantum dot films
摘要： For device printing, it is important for uniform films to be printed because the morphology of the film affects the performance of the device in inkjet printing. In this study, to prepare stable and well-dispersed ink, polyacrylate and silicone surfactant BD-3033H were added to ink. Then a uniform quantum dot (QD) film was obtained by optimizing the polyacrylate and silicone surfactant contents of the ink as well as the substrate temperature. The change of the polyacrylate structure from a curly chain structure to a three-dimensional network structure blocked the outward flow of QDs. Silicone surfactant BD-3033H caused Marangoni flow and made the QDs flow inward. When the substrate temperature was increased, the solvent evaporation rate was accelerated, the contact line was pinned, and the outward flow was enhanced, which changed the film structure from convex to flat. Finally, when the polyacrylate content was 12 wt%, the silicone surfactant BD-3033H content was 0.10 wt%, the substrate temperature was 40°C, and the coffee ring effect was eliminated. A uniform QD film was printed, providing a technical guarantee for the fabrication of QD devices in the future.
关键词： polyacrylate,coffee ring,Quantum dot film,silicone surfactant,inkjet printing
更新于2025-09-16 10:30:52