Electronic Materials Letters最新文献_第10页

Thermoelectric Transport Properties of Co0.5Fe0.5Se2, Co0.5Fe0.5Te2, and Their Solid-Solution Compositions Co0.5Fe0.5Se2、Co0.5Fe0.5Te2 及其固溶体化合物的热电传输特性

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-09-22 DOI: 10.1007/s13391-023-00459-8

Sang Jeong Park, Seyun Kim, Okmin Park, Se Woong Lee, Sang-il Kim

Transition-metal chalcogenides with tunable electronic transport properties and unique crystal structures have attracted much attention as potential thermoelectric materials. In this study, the electrical, thermal, and thermoelectrical transport properties of Co_0.5Fe_0.5Se₂, Co_0.5Fe_0.5Te₂ and a series of solid-solution compositions (Co_0.5Fe_0.5(Se_1−yTe_y)₂, y = 0.25, 0.5, and 0.75) were investigated. Co_0.5Fe_0.5Se₂ and Co_0.5Fe_0.5Te₂ polycrystalline alloys exhibited high power factors of 1.37 and 1.53 mW/mK² at 600 K, respectively, and their solid-solution compositions exhibited lower power factors between 0.38 and 0.81 mW/mK². The lattice thermal conductivities of Co_0.5Fe_0.5Se₂ and Co_0.5Fe_0.5Te₂ were 2.87 and 1.71 W/mK at 300 K, respectively, and their solid-solution compositions exhibited lower lattice thermal conductivities between 0.96 and 1.98 W/mK. Consequently, the thermoelectric figure of merit (zT) of the Co_0.5Fe_0.5Se₂ and Co_0.5Fe_0.5Te₂ polycrystalline alloys was 0.16 and 0.18 at 600 K, respectively, and the zT of their solid-solution composition exhibited lower values between 0.04 and 0.09. As the solid-solution composition exhibited a lower thermoelectric performance than the Co_0.5Fe_0.5Se₂ and Co_0.5Fe_0.5Te₂ polycrystalline alloys, the lower thermoelectric performance was analyzed and discussed.

Graphical Abstract

作为一种潜在的热电材料，具有可调电子传输特性和独特晶体结构的过渡金属卤化物备受关注。本研究调查了 Co0.5Fe0.5Se2、Co0.5Fe0.5Te2 和一系列固溶体成分（Co0.5Fe0.5(Se1-yTey)2, y = 0.25、0.5 和 0.75）的电学、热学和热电传输特性。Co0.5Fe0.5Se2 和 Co0.5Fe0.5Te2 多晶合金在 600 K 时的功率因数分别高达 1.37 和 1.53 mW/mK2，而其固溶体成分的功率因数则较低，介于 0.38 和 0.81 mW/mK2 之间。在 300 K 时，Co0.5Fe0.5Se2 和 Co0.5Fe0.5Te2 的晶格热导率分别为 2.87 和 1.71 W/mK，它们的固溶体成分表现出较低的晶格热导率，介于 0.96 和 1.98 W/mK 之间。因此，在 600 K 时，Co0.5Fe0.5Se2 和 Co0.5Fe0.5Te2 多晶合金的热电功勋值（zT）分别为 0.16 和 0.18，而其固溶体成分的 zT 值较低，介于 0.04 和 0.09 之间。由于固溶体成分的热电性能低于 Co0.5Fe0.5Se2 和 Co0.5Fe0.5Te2 多晶合金，因此对其较低的热电性能进行了分析和讨论。

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引用次数: 0

Copper, Palladium, and Reduced Graphene Oxide Co-doped Layered WS2/WO3 Nanostructures for Electrocatalytic Hydrogen Generation 用于电催化制氢的铜、钯和还原石墨烯氧化物共掺杂层状 WS2/WO3 纳米结构

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-09-12 DOI: 10.1007/s13391-023-00458-9

Vipin Kumar, Rajneesh Kumar Mishra, Le Gia Trung, Pushpendra Kumar, Sagar M. Mane, Jae Cheol Shin, Jin Seog Gwag

Fossil fuels have a vital role in global energy resources. The burning of fossil fuels produces pollutants and harms the environment. These environmental problems can be solved by searching for a substitute for fossil fuels. Hydrogen production by water electrolysis has emerged as a promising substitute. It is a green, clean, and renewable energy source. Low-cost water is abundant on the Earth. The metal and its composite material have been used to develop water electrolysis. Among these composite catalytic materials, WS₂/WO₃ composite catalyst is well-known for its excellent physical and chemical behavior in water electrolysis to produce hydrogen. Engineered catalysts can further enhance the catalytic performance. Therefore, we investigate and analyze the catalytic performance of copper (Cu), palladium (Pd), and r-GO co-doped WS₂/WO₃ composite material for water electrolysis to produce green, clean, and renewable hydrogen energy by hydrogen evolution reaction (HER). The hydrothermal synthesis method is used to prepare the WS₂/WO₃ composite material co-doped with Cu, Pd, and r-GO. The co-doping is favorable for fast charge transfer by providing many active catalytic sites for HER and enhancing the HER catalytic performance. Therefore, the co-doped tungsten disulfide/oxide could be a potential composite material for efficient water electrolysis for clean and renewable hydrogen production by electrochemical water electrolysis.

Graphical Abstract

化石燃料在全球能源资源中发挥着至关重要的作用。化石燃料的燃烧会产生污染物，对环境造成危害。这些环境问题可以通过寻找化石燃料的替代品来解决。水电解制氢已成为一种前景广阔的替代品。它是一种绿色、清洁和可再生能源。地球上有大量低成本的水。金属及其复合材料已被用于开发水电解。在这些复合催化材料中，WS2/WO3 复合催化剂因其在电解水制氢过程中优异的物理和化学性能而闻名。工程催化剂可进一步提高催化性能。因此，我们研究并分析了铜（Cu）、钯（Pd）和r-GO共掺杂的WS2/WO3复合材料在水电解中的催化性能，以利用氢进化反应（HER）生产绿色、清洁和可再生的氢能。该研究采用水热合成法制备了共掺杂 Cu、Pd 和 r-GO 的 WS2/WO3 复合材料。共掺杂为 HER 提供了许多活性催化位点，有利于电荷的快速转移，从而提高 HER 的催化性能。因此，共掺杂的二硫化钨/氧化物可以成为一种潜在的复合材料，用于高效电解水，通过电化学电解水法生产清洁和可再生氢气。

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引用次数: 0

Electrodeposited Ternary CuNiMo Catalysts for Alkaline Hydrogen Oxidation 用于碱性氢氧化的电沉积三元铜镍钼催化剂

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-09-10 DOI: 10.1007/s13391-023-00457-w

Hong Seong Park, Kyeong-Rim Yeo, Won Suk Jung, Soo-Kil Kim

In this study, we investigated ternary transition metal catalysts composed of Cu, Ni, and Mo for application to hydrogen oxidation reaction (HOR) in alkaline electrolyte. A series of catalysts with a wide range of elemental compositions were fabricated by a simple electrodeposition method, and their material and electrochemical properties were investigated. In particular, to avoid inaccurate activity measurements due to oxidation and reduction of the transition metal-based catalysts during the HOR test, the electrochemical measurements were performed in both H₂- and N₂-saturated electrolytes, and the results were compared. The fabricated CuNiMo catalyst with an optimized composition exhibited an excellent HOR activity of 2.03 mA cm⁻² at 0.1 V_RHE, while the current density decreased only by 0.55 mA cm⁻² after 3000 cycles. The enhanced HOR activity is attributed to the combined effects of the modified crystal structure, increased surface area, alloying effects beneficial to the hydrogen binding energy and OH⁻ binding energy, and appropriate surface compositions between the H-adsorbing metallic state and OH-adsorbing oxophilic states. The characteristics of the catalyst demonstrated in this study can provide insights for the development of non-precious catalysts for HOR in alkaline electrolytes.

Graphical Abstract

本研究探讨了由铜、镍和钼组成的三元过渡金属催化剂在碱性电解液中氢氧化反应（HOR）中的应用。通过简单的电沉积方法制备了一系列元素组成范围广泛的催化剂，并研究了它们的材料和电化学特性。特别是，为了避免在 HOR 测试过程中由于过渡金属基催化剂的氧化和还原而导致活性测量不准确，电化学测量同时在 H2- 和 N2 饱和电解质中进行，并对结果进行了比较。具有优化成分的铜镍钼催化剂在 0.1 VRHE 条件下表现出 2.03 mA cm-2 的优异 HOR 活性，而电流密度在 3000 次循环后仅下降了 0.55 mA cm-2。HOR 活性的提高归功于改良的晶体结构、增大的表面积、有利于氢结合能和羟基结合能的合金效应以及吸附 H 的金属态和吸附羟基的亲氧化态之间适当的表面成分的综合作用。本研究中展示的催化剂特性可为开发用于碱性电解质中 HOR 的非贵金属催化剂提供启示。

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引用次数: 0

Improvement of Microwave Dielectric Properties of MgTiO3 Ceramics by Ti-Site Complex Substitution ti位络合物取代改善MgTiO3陶瓷的微波介电性能

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-09-05 DOI: 10.1007/s13391-023-00456-x

Jong Seok Chung, Eung Soo Kim

Microwave dielectric properties of MgTi_1-x(Mn_1/3Nb_2/3)_xO₃ (0 ≤ x ≤ 0.05) ceramics were investigated based on their crystal structure characteristics. For the specimens sintered at 1400 °C for 4 h, complete solid solutions with a single phase and an ilmenite structure were obtained for the entire range of compositions. The quality factor (Qf) was dependent on the average Ti-site covalency related to the electronegativity difference and the reduction state of Ti⁴⁺. MgTi_0.995(Mn_1/3Nb_2/3)_0.005O₃ exhibited the highest Qf value of 212,000 GHz owing to the high average covalency obtained from the Rietveld refinement of X-ray Diffraction patterns, high binding energy, and small full width at half maximum of Ti 2p peaks, as confirmed by X-ray Photoelectron Spectroscopy of MgTiO₃ –based ceramics. The temperature coefficients of the resonant frequency (TCF) of MgTiO₃-based ceramics were dependent on the degree of average oxygen octahedral distortion of the ilmenite structure. The dielectric constant (K) was affected by the theoretical dielectric polarizability of the constituent ions of sintered specimens. Excellent microwave dielectric properties were obtained for MgTi_0.995(Mn_1/3Nb_2/3)_0.005O₃; K = 18.05, Qf = 212,000 GHz, TCF = − 37.04 ppm/°C. The microwave dielectric properties were improved by substituting (Mn_1/3Nb_2/3)⁴⁺ for Ti⁴⁺ in MgTiO₃-based ceramics.

Graphical Abstract

根据 MgTi1-x(Mn1/3Nb2/3)xO3（0 ≤ x ≤ 0.05）陶瓷的晶体结构特征，研究了其微波介电性能。对于在 1400 °C 下烧结 4 小时的试样，在整个成分范围内都获得了具有单相和钛铁矿结构的完整固溶体。品质因数（Qf）取决于与电负性差异和 Ti4+ 的还原状态有关的平均 Ti 位共价。MgTi0.995(Mn1/3Nb2/3)0.005O3 的 Qf 值最高，达到 212,000 GHz，这是因为根据 X 射线衍射图样的里特维尔德细化得到的平均共价率高、结合能高、Ti 2p 峰的半最大全宽小，这一点已通过 MgTiO3 基陶瓷的 X 射线光电子能谱分析得到证实。MgTiO3 基陶瓷的共振频率温度系数（TCF）取决于钛铁矿结构的八面体平均氧畸变程度。介电常数（K）受烧结试样中组成离子的理论介电极化率的影响。MgTi0.995(Mn1/3Nb2/3)0.005O3 获得了优异的微波介电性能；K = 18.05，Qf = 212,000 GHz，TCF = - 37.04 ppm/°C。通过在 MgTiO3 基陶瓷中用 (Mn1/3Nb2/3)4+ 代替 Ti4+，微波介电性能得到了改善。图文摘要

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引用次数: 0

A Soluble ‘Ba(Ni-ett)’ (ett = 1,1,2,2-Ethenetetrathiolate) Derived Thermoelectric Material 可溶性‘Ba（Ni ett）’（ett = 1,1,2,2-四硫代乙烯酯）衍生的热电材料

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-09-01 DOI: 10.1007/s13391-023-00454-z

Yaoyang Hu, Geoffrey Rivers, Michael P. Weir, David B. Amabilino, Christopher J. Tuck, Ricky D. Wildman, Oleg Makarovsky, Simon Woodward

We describe the synthesis and characterisation of the first of a new class of soluble ladder oligomeric thermoelectric material based on previously unutilised ethene-1,1,2,2-tetrasulfonic acid. Reaction of Ba(OH)₂ and propionic acid at a 1:1 stoichiometry leads to the formation of the previously unrecognised soluble [Ba(OH)(O₂CEt)]⋅H₂O. The latter when used to hydrolyse 1,3,4,6-tetrathiapentalene-2,5-dione (TPD), in the presence of NiCl₂, forms a new material whose elemental composition is in accord with the formula [(EtCO₂Ba)₄Ni₈{(O₃S)₂C = C(SO₃)₂}₅]⋅22H₂O (4). Compound 4 can be pressed into pellets, drop-cast as DMSO solutions or ink-jet printed (down to sub-mm resolutions). While its room temperature thermoelectric properties are modest (σ_max 0.04 S cm⁻¹ and Seebeck coefficient, α_max − 25.8 μV K⁻¹) we introduce a versatile new oligomeric material that opens new possible synthetic routes for n-type thermoelectrics.

Graphical Abstract

我们描述了基于以前未利用的乙烯-1,1,2,2-四磺酸的第一种新型可溶性梯形低聚热电材料的合成和特性。Ba(OH)2和丙酸以1:1的比例发生反应，形成了以前未曾认识到的可溶性[Ba(OH)(O2CEt)]⋅H2O。后者在 NiCl2 的存在下用于水解 1,3,4,6-四硫杂戊烯-2,5-二酮（TPD）时，会形成一种新材料，其元素组成符合[(EtCO2Ba)4Ni8{(O3S)2C = C(SO3)2}5]⋅22H2O（4）式。化合物 4 可压制成颗粒、滴铸成 DMSO 溶液或喷墨打印（分辨率可达亚毫米）。虽然它的室温热电性能不高（σmax 0.04 S cm-1 和塞贝克系数 αmax - 25.8 μV K-1），但我们介绍了一种多功能的新型低聚物材料，它为 n 型热电材料开辟了新的合成途径。

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引用次数: 0

Effects of Surface Oxidation on the Magnetic Properties of Fe-Based Amorphous Metal Powder Made by Atomization Methods 表面氧化对雾化法制备铁基非晶金属粉末磁性能的影响

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-08-28 DOI: 10.1007/s13391-023-00455-y

Tae-Kyung Lee, Seung-Wook Kim, Dae-Yong Jeong

The demand for soft magnetic amorphous metal powders with high saturation magnetization values and low energy loss has increased to achieve high-performance inductors for mobile electronic devices. In this study, Fe-based Fe_92.3Si_3.5B_3.0C_0.7P_0.5 (wt.%) amorphous metal powders were prepared using different atomization methods for controlling the surface oxidation of the metal alloy powder. Conventional high-pressure water atomization and the newly developed high-speed water screen atomization methods were used for preparation. Regardless of the preparation methods, both alloy powders were amorphous, and their magnetic flux density (Bs) values were more than 165 emu/g. Compared to the powders from the conventional high-pressure water atomization method, the amorphous metal powder manufactured using the high-speed water screen atomization process had lower eddy current loss because of the formation of a thin and uniform oxide layer. Furthermore, the magnetic properties of the consolidated magnetic cores fabricated with the amorphous powders produced by the high-speed water screen atomization method using compact-pressing techniques were characterized. Magnetic powders with fewer surface oxidation layers exhibited increased initial permeability and a smaller coercive field, leading to a lower core loss value. The magnetic core made from Fe_92.3Si_3.5B_3.0C_0.7P_0.5 (wt.%) amorphous powder with an oxide content of 0.12 (wt.%) using the high-speed water screen atomization method exhibited an initial permeability of 25 in the frequency range up to 5 MHz, and a loss of 237 mW/cm³ with B_m = (0.2,{text{T}}) at 1 MHz.

Graphical Abstract

为实现移动电子设备的高性能电感器，对具有高饱和磁化值和低能量损失的软磁非晶金属粉末的需求日益增加。本研究采用不同的雾化方法制备了Fe92.3Si3.5B3.0C0.7P0.5（重量百分比）非晶金属粉末，以控制金属合金粉末的表面氧化。制备方法包括传统的高压水雾化法和新开发的高速水筛雾化法。无论采用哪种制备方法，两种合金粉末都是无定形的，其磁通密度（Bs）值都大于 165 emu/g。与传统高压水雾化法制备的粉末相比，高速水筛网雾化法制备的非晶态金属粉末由于形成了薄而均匀的氧化层，因此涡流损耗较低。此外，还对使用高速水筛网雾化法生产的非晶粉末通过压制技术制造的固结磁芯的磁性能进行了表征。表面氧化层较少的磁粉显示出更高的初始磁导率和更小的矫顽力场，从而导致更低的磁芯损耗值。使用高速水筛分雾化法由氧化物含量为 0.12（重量百分比）的 Fe92.3Si3.5B3.0C0.7P0.5（重量百分比）无定形粉末制成的磁芯在高达 5 MHz 的频率范围内显示出 25 的初始磁导率，在 1 MHz 时 Bm = (0.2,{text/{T}}/)的损耗为 237 mW/cm3。

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引用次数: 0

Conductive Paste Inks Prepared Using Ionic-Liquid-Stabilized Metal Nanoparticle Fluids and their Sintering Effect 离子液体稳定金属纳米粒子制备导电浆料及其烧结效果

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-08-27 DOI: 10.1007/s13391-023-00451-2

Tae-Gyun Kwon, Younghoon Kim

Conductive paste inks have received considerable attention as facile conductive materials for the formation of electrode layers. However, conventional paste inks result in films with poor surface morphology. In addition, they require a high thermal annealing temperature for achieving high electrical conductivity because of their organic/inorganic composite structure, in which nanosized metal particles and polymeric organic binders are mixed in solvents. In this work, we prepare solvent-free and polymeric-binder-free metal nanoparticle (NP) fluids, which can be used as facile conductive pastes for forming an electrode layer after sintering at a considerably low temperature. We employ thiol-terminated imidazolium-type ionic liquid (IL-SH) molecules with a small molecular weight and fluidic behavior as the surface ligands of Ag NPs. IL-SH-stabilized Ag NPs exhibit fluidic behavior and metallic conducting properties at a considerably low sintering temperature of 250 °C.

Graphical Abstract

导电浆状油墨作为一种易于形成电极层的导电材料，受到了广泛关注。然而，传统浆状油墨形成的薄膜表面形态不佳。此外，由于其有机/无机复合结构，即纳米级金属颗粒和聚合物有机粘合剂在溶剂中混合，因此需要较高的热退火温度才能实现高导电性。在这项工作中，我们制备了不含溶剂和聚合物粘合剂的金属纳米粒子（NP）流体，这种流体可用作导电浆料，在相当低的温度下烧结后形成电极层。我们采用分子量小、流动性好的硫醇端咪唑离子液体（IL-SH）分子作为银纳米粒子的表面配体。IL-SH稳定的Ag NPs在250 °C的相当低的烧结温度下表现出流体行为和金属导电特性。

引用次数: 0

Electrodeposited Hierarchical Silver Network Transparent Conducting Electrodes with Excellent Optoelectronic Properties and Mechanical Flexibility 具有优异光电特性和机械柔性的电沉积分层银网络透明导电电极

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-08-24 DOI: 10.1007/s13391-023-00453-0

Eunyeong Yang, Seoin Kang, Sanghyun Jeong, Kihyun Shin, Jung-Sub Wi, Joon Sik Park, Sangyeob Lee, Choong-Heui Chung

Mechanically flexible transparent conductive electrodes (TCEs) with high optoelectronic performance are essential for flexible or wearable optoelectronic devices, which are currently receiving a considerable amount of attention. In this study, we investigate the structural, electrical, optical and mechanical properties of electrodeposited hierarchical silver network TCEs consisting of two layers of silver nanowires (AgNWs) and a silver micromesh. Hierarchical structures are known to improve the optoelectronic properties of network-type TCEs. To fabricate an electrodeposited hierarchical network, a AgNW solution is first spun onto a substrate to form randomly distributed AgNWs, and a silver micromesh is then formed on the AgNWs. Subsequently, silver is electrodeposited onto the hierarchical network. As a result of the electrodeposition, AgNW-AgNW and AgNW-silver micromesh contacts are effectively welded, and the dimensions of the AgNWs and the silver micromesh are optimized to maximize the figure of merit of the TCE. Furthermore, the electrodeposited hierarchical silver network shows excellent mechanical flexibility and much less degradation of its sheet resistance than that experienced by ITO upon repeated convex and concave bending. Its resulting optoelectronic and mechanically flexible performance is superior to that of commercialized ITO.

Graphical Abstract

具有高光电性能的机械柔性透明导电电极（TCE）对于柔性或可穿戴光电设备至关重要，目前正受到广泛关注。在本研究中，我们研究了由两层银纳米线（AgNWs）和银微网组成的电沉积分层银网络 TCE 的结构、电气、光学和机械特性。众所周知，分层结构可改善网络型 TCE 的光电特性。为了制造电沉积分层网络，首先将银纳米线溶液纺到基底上，形成随机分布的银纳米线，然后在银纳米线上形成银微网。随后，银被电沉积到分层网络上。电沉积的结果是，AgNW-AgNW 和 AgNW-银微网接触得到有效焊接，AgNW 和银微网的尺寸得到优化，从而最大限度地提高了 TCE 的性能。此外，电沉积分层银网络具有出色的机械柔韧性，在反复凸凹弯曲时，其薄层电阻的衰减程度远低于 ITO。其光电和机械柔性性能均优于已商业化的 ITO。

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引用次数: 0

Improved Performance of Transparent MoS2 Thin-Film Transistor with IZO Electrodes by Air Thermal Annealing 空气热退火改善IZO电极透明MoS2薄膜晶体管的性能

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-08-23 DOI: 10.1007/s13391-023-00450-3

Ju Won Kim, Jin Gi An, Guen Hyung Oh, Joo Hyung Park, TaeWan Kim

Molybdenum disulfide (MoS₂) grown via metal-organic chemical vapor deposition is known to exhibit high transparency and superior quality. Transparent thin-film transistor (TFT) based on a multilayer MoS₂ film and indium zinc oxide (IZO) using a representative transparent conducting oxide as source and drain electrodes indicate more than 70% transmittance in the visible wavelength. However, the device performance is limited by the large Schottky barrier height corresponding to the high work function of IZO (~ 5.1 eV) and surface impurities generated during the wet transfer process and subsequent oxidation. In this study, we addressed this problem by employing air thermal annealing to improve the TFT device performance. Consequently, contact resistance is reduced ~ 10 times, and the field-effect mobility and on/off ratio measured using ion-gel side gate, which are important parameters for TFT device operation, were enhanced by ~ 59 and ~ 81 times, respectively.

Graphical abstract

众所周知，通过金属有机化学气相沉积生长的二硫化钼（MoS2）具有高透明度和卓越的品质。基于多层 MoS2 薄膜和氧化铟锌（IZO）的透明薄膜晶体管（TFT）使用具有代表性的透明导电氧化物作为源极和漏极，在可见光波段的透过率超过 70%。然而，由于 IZO 的功函数较高（约 5.1 eV），因此肖特基势垒高度较大，而且在湿法转移过程和随后的氧化过程中会产生表面杂质，从而限制了器件的性能。在本研究中，我们采用空气热退火来改善 TFT 器件的性能，从而解决了这一问题。因此，接触电阻降低了 ~ 10 倍，使用离子凝胶侧栅测量的场效应迁移率和开/关比（TFT 器件运行的重要参数）分别提高了 ~ 59 倍和 ~ 81 倍。

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引用次数: 0

Manipulation of Hole and Exciton Distributions in Organic Light-Emitting Diodes with Dual Emission Layers 双发射层有机发光二极管中空穴和激子分布的操纵

IF 2.1 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters

Pub Date : 2023-08-23 DOI: 10.1007/s13391-023-00452-1

Suk-Ho Song, Jae-In Yoo, Hyo-Bin Kim, Sung-Cheon Kang, Kanghoon Kim, Sung-Jae Park, Qun Yan, Jang-Kun Song

The efficiency improvement of organic light-emitting diodes (OLEDs) is important but challenging. Here, we introduce a unique OLED with a hole modulation layer (HML) in the middle of its emission layer (EML). The external quantum efficiency and power efficiency can be improved by approximately 58% when an HML with optimized thickness is inserted. HML insertion can efficiently retard hole flow, thus improving (i) exciton distribution uniformity and (ii) local electron–hole charge balance. A systematic study of the individual contributions of two EMLs separated by the HML shows that the former factor dominantly works at low current densities (< 10 mA/cm²), whereas the latter factor functions over the entire current density range of the OLED. Therefore, the efficiency improvement is greatest at low current densities, which aligns with the typical operating range in display applications. The results provide a deeper understanding of the OLED emission mechanism, and the proposed OLED structure can significantly benefit high-performance OLED displays.

Graphical Abstract

提高有机发光二极管（OLED）的效率非常重要，但也极具挑战性。在这里，我们引入了一种独特的有机发光二极管，在其发射层（EML）中间有一个空穴调制层（HML）。当插入具有优化厚度的 HML 时，外部量子效率和功率效率可提高约 58%。插入 HML 可以有效地延缓空穴流，从而改善（i）激子分布均匀性和（ii）局部电子-空穴电荷平衡。对被 HML 分隔开来的两个 EML 的各自贡献进行的系统研究表明，前一个因素主要在低电流密度（10 mA/cm2）时起作用，而后一个因素则在 OLED 的整个电流密度范围内起作用。因此，在低电流密度时效率提高最大，这与显示应用中的典型工作范围一致。这些结果加深了人们对 OLED 发射机制的理解，而所提出的 OLED 结构可显著提高高性能 OLED 显示屏的性能。

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引用次数: 0