- 标题
- 摘要
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- 实验方案
- 产品
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Mg-Doped ZnO Nanoparticle Films as the Interlayer between the ZnO Electron Transport Layer and InP Quantum Dot Layer for Light-Emitting Diodes
摘要： Because the wide emission spectrum tunability which range from the visible region to the near-infrared, InP based colloidal quantum dots (QDs) show great promise for use in next-generation full-color displays and solid state lighting. The performance-improved InP QD based light-emitting devices (QLEDs) were fabricated by using Mg doped-ZnO nanoparticles (ZnMgO NPs) as an interlayer between ZnO electron transport layer and active InP QD layer. It is found that ZnMgO NPs can reduce electron injection and suppress exciton quenching which is attributed to the improvement of charge balance in the devices. We successfully demonstrated higher maximum current efficiencies of 5.46 and 5.91 cd/A than the references (2.31 and 2.36 cd/A) without the ZnMgO NP layer in highly efficient red and green QLEDs, respectively. These results signify an effective approach to improve heavy-metal-free QLEDs for commercial applications.
关键词： InP quantum dots,Mg doped-ZnO,electron transport layer,light-emitting diodes,charge balance
更新于2025-09-23 15:21:01
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An effective strategy to boost 3D perovskite light-emitting diode performance via solvent mixing strategy
摘要： In this study, we demonstrate a simple method to achieve highly efficient perovskite light-emitting diode (PeLED) via casting the neat methylammonium bromide (MABr) in mixed solvents with different solubility on top of the perovskite layer for bulk recrystallization and interfacial passivation. The perovskite crystals reacting with MABr can be reformed orderly and stereoscopically with a reduced domain size on surface and reduced grain boundaries in bulk, which is advantageous to obtain strong fluorescence intensity and long exciton lifetime. The remaining MABr molecule that does not react with perovskite can attach on the recrystallized perovskite surface to develop a passivation layer, which can effectively eliminate exciton interface recombination in PeLEDs. The optimized PeLED exhibits a maximum luminance of 27692.2 cd m-2, which is more than 11 times and 2 times higher than the control device without MABr treatment and the control device with high MABr molar ratio and thin perovskite film thickness, respectively. This work provides an effective strategy to boost PeLED performance by optimizing mixed solvent ratios and concentrations of organic ligand MABr without changing the thickness of the emitting layer.
关键词： charge balance,morphological manipulation,passivation,perovskite light-emitting diode,recrystallization
更新于2025-09-23 15:19:57
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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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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Optimized Quantum Dot Light-emitting-device with Insulating Layer
摘要： We reported the preparation of CdSe/CdS/ZnS based quantum dot light-emitting-devices (QLED) with an ultra-thin PMMA layer. This PMMA layer between the quantum dots layer and the electron-transport layer retards the electron current and results in a more balanced electron and hole injecting into emissive quantum dot layer. The optimized charge balance enhanced the device external quantum efficiency (EQE). The results show that the precise control of the PMMA layer thickness is quite important, otherwise, leading to degraded device efficiency and increased turn on voltage.
关键词： insulating layer,Quantum dot light emitting device,Charge balance
更新于2025-09-16 10:30:52
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Control of carrier injection and transport in quantum dot light emitting diodes (QLEDs) via modulating Schottky injection barrier and carrier mobility
摘要： Carrier injection and transport in the quantum dot (QD) layer was modulated by tuning the Schottky injection barrier and mobility of charge transport layers. The analyses indicate that stages of the J-V curve for hole injection must match with those of electron injection to achieve the charge balance in the QD layer. In addition, it was demonstrated that not only the parameters investigated but also other parameters such as charge trap density and energy levels must be considered to enhance the e?ciency of the QLEDs. With the improved charge balance in the QD layer, the current e?ciency of the quantum dot light-emitting diode display was improved from 26 to 40 cd/A.
关键词： Schottky injection barrier,light emitting diodes,quantum dot,charge balance,carrier mobility
更新于2025-09-12 10:27:22
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CdSe/ZnS Quantum-Dot Light-Emitting Diodes With Spiro-OMeTAD as Buffer Layer
摘要： We report a high-ef?cient green CdSe/ZnS quantum-dot light-emitting diode (QLED) using 2,2’,7,7’-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9’-Spirobi?uorene (Spiro-OMeTAD) as an electron buffer layer. The high lowest unoccupied molecular orbital level of Spiro-OMeTAD suppresses the electron transfer and promotes the charge balance. The external quantum ef?ciency (EQE) of the green QLED device is increased by 1.93 times to 14.65%, and the brightness is increased by 1.37 times to 55 760 cd/m2. The results show that the Spiro-OMeTAD layer can effectively prevent excessive electron injection into QDs, and balance the combination of electron and hole carriers.
关键词： charge balance,light-emitting diodes,quantum dots (QDs),Buffer layer
更新于2025-09-12 10:27:22
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P‐9.6: Highly Luminescent Blue Quantum Dots Light‐Emitting Diodes
摘要： A better charge balance is realized for blue quantum dot light-emitting diodes (QLEDs) through doping the charge transport layer (CTL) to improve hole injection and suppress redundant electrons. High performance blue QLEDs were achieved by fine-tuning the charge balance within the emitting layer.
关键词： electron-transporting layer,quantum dots light-emitting diodes,charge balance,hole-transporting layer,hybrid charge transporting layer
更新于2025-09-11 14:15:04
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An efficient cadmium free inverted red quantum dot light emitting diodes
摘要： Here, we report an efficient inverted red indium phosphide (InP) comprised QD (InP/ZnSe/ZnS, core/shell structure) light-emitting diode (QLED) by modulating an interfacial contact between the electron transport layer and emissive InP-QDs and applying self-aging approach. The red InP-QLED with optimized interfacial contact exhibits a significant improvement in maximum external quantum efficiency and current efficiency from 4.42% to 10.2% and 4.70 cd/A to 10.8 cd/A, respectively, after 69 days of self-aging, which is an almost 2.3-fold improvement compared with the fresh device. The analysis indicates the consecutive reduction in electron injection and accumulation in the emissive QD due to changes in the conduction band minimum of ZnMgO (0.1 eV after 10 days of storage times) through a downward vacuum level shift according to the aging times. During the device aging periods, the oxygen vacancies of ZnMgO reduces, which leads to lower the conductivity of ZnMgO. As a result, the improvement of charge balance in the device with the suppression of exciton quenching at the interface of ZnMgO and InP-QD.
关键词： Cadmium-free quantum dots,charge balance,charge carrier injection layers,inverted structure,light emitting diode
更新于2025-09-11 14:15:04
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Improving the charge balance and performance of CdSe/ZnS quantum-dot light-emitting diodes with a sputtered zinc-tin-oxide electron-transport layer and a thermally evaporated tungsten-oxide charge-restricting layer
摘要： The charge carrier balance and performance of CdSe/ZnS quantum-dot light-emitting diodes (QD-LEDs) with a vacuum-deposited electron-transport layer (ETL) and carrier-restricting layer (CRL) were successfully improved. Optimizing the fabrication process of the reactively sputtered zinc-tin-oxide (ZTO) ETL and adopting a thermally evaporated tungsten-oxide (WOx) CRL improved the electron-hole balance, thus leading to QD-LEDs with improved performance. Impedance spectroscopy analysis was successfully exploited in investigating charge carrier injection into each layer of the QD-LED and electron-hole recombination behaviors. The QD-LED with optimized ZTO ETL and without WOx CRL exhibited 2600 cd m?2 luminance and 3.2 cd A?1 current efficiency, and the QD-LED with both optimized ZTO ETL and a WOx CRL exhibited 3900 cd m?2 luminance and 5.1 cd A?1 current efficiency. These results imply a practical method for improving the electron-hole balance and performance of QD-LEDs, and provide a reliable technique for analyzing the carrier behavior of QD-LEDs.
关键词： CdSe/ZnS quantum-dot,light-emitting diodes,tungsten-oxide,charge balance,zinc-tin-oxide,impedance spectroscopy
更新于2025-09-11 14:15:04