Electronic Materials Letters最新文献_第3页

Phase Formation Behavior and Thermoelectric Transport Properties of Solid Solution Composition Between SnTe and InTe

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

Electronic Materials Letters

Pub Date : 2024-11-16 DOI: 10.1007/s13391-024-00529-5

BeomSoo Kim, TaeWan Kim, Seungchan Seon, Okmin Park, Hyungyu Cho, Weon Ho Shin, Sang-il Kim

Alloys based on SnTe have been widely studied for their eco-friendly characteristics and good electrical performance in the high-temperature range above 600 K. In this study, SnTe-InTe solid solution alloy compositions of Sn_1 − xIn_xTe (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were investigated for their phase formation behavior and thermoelectric properties. A single cubic SnTe phase was formed in x ≤ 0.4 samples, while x = 0.6 and 0.8 samples formed multi-phase with a tetragonal InTe phase. The carrier mobility gradually decreased with increasing x in the single cubic phase region (x = 0-0.4), and a drastic reduction of 58% for x = 0.2 and 82% for x = 0.4, causing S and σ to decrease simultaneously compared to that of the pristine SnTe. Thus, the power factor gradually reduced to 0.06 mW/mK² for x = 0.4 compared to 1.57 mW/mK² for the pristine sample, as confirmed by the weighted mobility reduction behavior. The lattice thermal conductivity showed a gradual decrease in the simple cubic phase region, owing to the additional point defects formed by In substitution of Sn sites. Consequently, zT gradually decreased from 0.31 for the pristine to 0.02 for x = 0.4 sample due to the degradation of carrier transport properties, specifically Hall mobility, outweighing the total thermal conductivity reduction. The maximum zT value of 0.50 at 750 K was observed for InTe (x = 1.0). Additional analysis using the single-parabolic-band model indicated that zT enhancement through carrier concentration optimization was not feasible for the alloy samples.

Graphical Abstract

{"title":"Phase Formation Behavior and Thermoelectric Transport Properties of Solid Solution Composition Between SnTe and InTe","authors":"BeomSoo Kim, TaeWan Kim, Seungchan Seon, Okmin Park, Hyungyu Cho, Weon Ho Shin, Sang-il Kim","doi":"10.1007/s13391-024-00529-5","DOIUrl":"10.1007/s13391-024-00529-5","url":null,"abstract":"<div><p>Alloys based on SnTe have been widely studied for their eco-friendly characteristics and good electrical performance in the high-temperature range above 600 K. In this study, SnTe-InTe solid solution alloy compositions of Sn<sub>1 − x</sub>In<sub>x</sub>Te (<i>x</i> = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were investigated for their phase formation behavior and thermoelectric properties. A single cubic SnTe phase was formed in <i>x</i> ≤ 0.4 samples, while <i>x</i> = 0.6 and 0.8 samples formed multi-phase with a tetragonal InTe phase. The carrier mobility gradually decreased with increasing <i>x</i> in the single cubic phase region (<i>x</i> = 0-0.4), and a drastic reduction of 58% for <i>x</i> = 0.2 and 82% for <i>x</i> = 0.4, causing <i>S</i> and <i>σ</i> to decrease simultaneously compared to that of the pristine SnTe. Thus, the power factor gradually reduced to 0.06 mW/mK<sup>2</sup> for <i>x</i> = 0.4 compared to 1.57 mW/mK<sup>2</sup> for the pristine sample, as confirmed by the weighted mobility reduction behavior. The lattice thermal conductivity showed a gradual decrease in the simple cubic phase region, owing to the additional point defects formed by In substitution of Sn sites. Consequently, <i>zT</i> gradually decreased from 0.31 for the pristine to 0.02 for <i>x</i> = 0.4 sample due to the degradation of carrier transport properties, specifically Hall mobility, outweighing the total thermal conductivity reduction. The maximum <i>zT</i> value of 0.50 at 750 K was observed for InTe (<i>x</i> = 1.0). Additional analysis using the single-parabolic-band model indicated that <i>zT</i> enhancement through carrier concentration optimization was not feasible for the alloy samples.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 2","pages":"207 - 215"},"PeriodicalIF":2.1,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase-Separated 2D PbBiI5 Halide Memristor for Neuromorphic Computing 用于神经形态计算的2D相分离PbBiI5卤化物记忆电阻器

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

Electronic Materials Letters

Pub Date : 2024-11-08 DOI: 10.1007/s13391-024-00528-6

Hee Joon Jung

Here, we report on the two-dimensional (2D) (PbI₂)_0.5(BiI₃)_0.5 mixed halide memristor, which exhibits nonlinear conductance that surpasses the properties of the simple combination of PbI₂ and BiI₃ binaries. This 2D system is phase-separated into Bi-rich and Bi-poor nanoscale domains rather than forming a single homogeneous phase. Phase boundaries, predominantly featuring iodine vacancies or stacking faults, induce a novel memristive behavior along the c-axis, driven by ion transport perpendicular to the layered structure, making it promising for resistive switching memory (RRAM) applications. In-situ biasing transmission electron microscopy (TEM) reveals the formation of iodine filaments under sweep bias, with ion migration occurring mainly through phase boundaries in the out-of-plane direction. Direct observation of reversible filament formation in this phase-separated iodide system provides new insights into defect-mediated ion migration, resulting in nonlinear resistive switching, with potential applications in neuromorphic computing. The ability to track heavy anions like iodine in the halide memristor provides valuable insights into the similar correlation mechanisms between ion migration and defects in oxide or sulfide-based memristors. This capability could shed light on how defects influence ion transport in a broader range of materials, enhancing the development of resistive switching devices.

Graphical Abstract

在这里，我们报道了二维（2D）（PbI2）0.5(BiI3)0.5混合卤化物忆阻器，其非线性电导优于PbI2和BiI3二元结构的简单组合。该二维体系相分离为富bi和贫bi纳米级畴，而不是形成单一的均匀相。相边界主要以碘空位或堆叠错误为特征，在垂直于层状结构的离子输运驱动下，沿c轴诱导出一种新的记忆行为，使其有望用于电阻开关存储器（RRAM）应用。原位偏置透射电子显微镜（TEM）显示，在扫描偏置下，碘丝的形成，离子迁移主要发生在面外方向的相界上。直接观察这种相分离碘化物系统中可逆灯丝的形成，为缺陷介导的离子迁移提供了新的见解，从而导致非线性电阻开关，在神经形态计算中具有潜在的应用。在卤化物记忆电阻器中跟踪像碘这样的重阴离子的能力，为离子迁移与氧化物或硫化物基记忆电阻器缺陷之间的类似相关机制提供了有价值的见解。这种能力可以揭示缺陷如何影响更广泛材料中的离子输运，从而促进电阻开关器件的发展。图形抽象

{"title":"Phase-Separated 2D PbBiI5 Halide Memristor for Neuromorphic Computing","authors":"Hee Joon Jung","doi":"10.1007/s13391-024-00528-6","DOIUrl":"10.1007/s13391-024-00528-6","url":null,"abstract":"<div><p>Here, we report on the two-dimensional (2D) (PbI<sub>2</sub>)<sub>0.5</sub>(BiI<sub>3</sub>)<sub>0.5</sub> mixed halide memristor, which exhibits nonlinear conductance that surpasses the properties of the simple combination of PbI<sub>2</sub> and BiI<sub>3</sub> binaries. This 2D system is phase-separated into Bi-rich and Bi-poor nanoscale domains rather than forming a single homogeneous phase. Phase boundaries, predominantly featuring iodine vacancies or stacking faults, induce a novel memristive behavior along the c-axis, driven by ion transport perpendicular to the layered structure, making it promising for resistive switching memory (RRAM) applications. In-situ biasing transmission electron microscopy (TEM) reveals the formation of iodine filaments under sweep bias, with ion migration occurring mainly through phase boundaries in the out-of-plane direction. Direct observation of reversible filament formation in this phase-separated iodide system provides new insights into defect-mediated ion migration, resulting in nonlinear resistive switching, with potential applications in neuromorphic computing. The ability to track heavy anions like iodine in the halide memristor provides valuable insights into the similar correlation mechanisms between ion migration and defects in oxide or sulfide-based memristors. This capability could shed light on how defects influence ion transport in a broader range of materials, enhancing the development of resistive switching devices.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"32 - 40"},"PeriodicalIF":2.1,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced Thermoelectric Properties of FeSe2 Alloys by Lattice Thermal Conductivity Reduction by Cl Doping Cl掺杂降低FeSe2合金晶格热导率增强其热电性能

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

Electronic Materials Letters

Pub Date : 2024-11-07 DOI: 10.1007/s13391-024-00527-7

BeomSoo Kim, Hyungyu Cho, Okmin Park, Seungchan Seon, Sang-il Kim

Metal chalcogenides are widely studied as thermoelectric materials due to their finely tunable electronic transport properties over a wide temperature range. FeSe₂ has recently been considered a promising thermoelectric material with investigations focusing on restraining bipolar behavior through doping. In this study, a series of Cl-doped FeSe₂ compositions, a series of FeSe_2 − xCl_x (x = 0, 0.01, 0.025, and 0.05) compositions, were synthesized to investigate the influence of Cl doping. While the gradually decreasing lattice parameters with doping content x suggests successful doping up to x = 0.05, the hole concentration slightly decreased owing to electrons generated by the Cl doping. Nevertheless, the electrical conductivity and Seebeck coefficient show no systematic change with x owing to very low electron generating efficiency, and no distinctive enhancement of power factor is seen for the doped samples. On the other hand, the lattice thermal conductivity gradually and significantly decreased with x from 9.2 W/mK to 6.3 W/mK for x = 0.05 by 32% at 300 K, which is originated from the effective additional phonon scattering due to the difference in mass (55%) and size (9%) between Se²⁻ and Cl⁻ ions. Consequently, a thermoelectric figure of merit is increased to 0.073 from 0.057 at 600 K for x = 0.05.

Graphical Abstract

金属硫族化合物由于其在较宽的温度范围内具有良好的可调谐电子输运特性而作为热电材料被广泛研究。近年来，FeSe2被认为是一种很有前途的热电材料，研究重点是通过掺杂抑制双极行为。本研究合成了一系列掺杂Cl的FeSe2 - xClx （x = 0、0.01、0.025和0.05）组合物，以研究Cl掺杂对FeSe2 - xClx的影响。随着掺杂量x的增加，晶格参数逐渐减小，表明在x = 0.05时掺杂成功，但由于Cl掺杂产生了电子，空穴浓度略有下降。然而，由于电子产生效率非常低，电导率和塞贝克系数随x的变化没有系统的变化，并且在掺杂样品中没有看到明显的功率因数增强。另一方面，在300 K时，晶格热导率随x的增加而逐渐显著下降，从9.2 W/mK下降到6.3 W/mK (x = 0.05)，下降了32%，这是由于Se2−和Cl−离子之间质量（55%）和尺寸（9%）的差异造成的有效的额外声子散射。因此，当x = 0.05时，热电性能值从600 K时的0.057增加到0.073。图形抽象

{"title":"Enhanced Thermoelectric Properties of FeSe2 Alloys by Lattice Thermal Conductivity Reduction by Cl Doping","authors":"BeomSoo Kim, Hyungyu Cho, Okmin Park, Seungchan Seon, Sang-il Kim","doi":"10.1007/s13391-024-00527-7","DOIUrl":"10.1007/s13391-024-00527-7","url":null,"abstract":"<div><p>Metal chalcogenides are widely studied as thermoelectric materials due to their finely tunable electronic transport properties over a wide temperature range. FeSe<sub>2</sub> has recently been considered a promising thermoelectric material with investigations focusing on restraining bipolar behavior through doping. In this study, a series of Cl-doped FeSe<sub>2</sub> compositions, a series of FeSe<sub>2 − x</sub>Cl<sub>x</sub> (<i>x</i> = 0, 0.01, 0.025, and 0.05) compositions, were synthesized to investigate the influence of Cl doping. While the gradually decreasing lattice parameters with doping content <i>x</i> suggests successful doping up to <i>x</i> = 0.05, the hole concentration slightly decreased owing to electrons generated by the Cl doping. Nevertheless, the electrical conductivity and Seebeck coefficient show no systematic change with <i>x</i> owing to very low electron generating efficiency, and no distinctive enhancement of power factor is seen for the doped samples. On the other hand, the lattice thermal conductivity gradually and significantly decreased with <i>x</i> from 9.2 W/mK to 6.3 W/mK for <i>x</i> = 0.05 by 32% at 300 K, which is originated from the effective additional phonon scattering due to the difference in mass (55%) and size (9%) between Se<sup>2−</sup> and Cl<sup>−</sup> ions. Consequently, a thermoelectric figure of merit is increased to 0.073 from 0.057 at 600 K for <i>x</i> = 0.05.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"79 - 86"},"PeriodicalIF":2.1,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rapid Thermal Annealing under O2 Ambient to Recover the Deterioration by Gamma-Ray Irradiation in a-IGZO TFTs O2环境下快速热退火恢复γ射线辐照下a-IGZO tft的劣化

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

Electronic Materials Letters

Pub Date : 2024-10-15 DOI: 10.1007/s13391-024-00526-8

Minah Park, Jaewook Yoo, Hongseung Lee, Hyeonjun Song, Soyeon Kim, Seongbin Lim, Seohyeon Park, Jo Hak Jeong, Bongjoong Kim, Kiyoung Lee, Yoon Kyeung Lee, Keun Heo, Jiseok Kwon, Hagyoul Bae

Amorphous indium-gallium-zinc-oxide (a-IGZO) has been attracting great attention as a channel material for dynamic random access memory (DRAM) cell transistors due to its superior characteristics including low leakage current, large area deposition, and back-end-of-line (BEOL) compatibility. It should be clearly taken into account that DRAM will also be used in harsh environments such as military surveillance, aerospace, and nuclear power plants. Especially, these situations can cause inevitable and persistent degradation in long-term operations. When the a-IGZO thin film transistors (TFTs) were irradiated by gamma-ray with total doses of 500 Gy, threshold voltage (V_T) was negatively shifted and hysteresis (delta of V_T between forward and backward sweeps) was increased by creating a positive charge in gate insulator. The extracted density-of-states (DOS) and fitted model were employed to investigate the behavior of oxygen vacancy (V_O) in a-IGZO thin film. Electrical performance degraded by gamma-ray irradiation such as changes in V_T, border trap, tail acceptor-like states (g_TA(E)), and shallow donor-like states (g_SD(E)) were recovered through rapid thermal annealing (RTA) under the O₂ ambient.

Graphical Abstract

非晶铟镓锌氧化物（a- igzo）作为动态随机存取存储器（DRAM）电池晶体管的通道材料，由于其具有低漏电流、大面积沉积和后端线（BEOL）兼容性等优异特性而备受关注。DRAM还将在军事监视、航空航天、核电站等恶劣环境中使用，这一点必须考虑在内。特别是，这些情况在长期操作中可能导致不可避免的持续退化。当总剂量为500 Gy的γ射线照射a- igzo薄膜晶体管（TFTs）时，阈值电压（VT）发生负移，栅极绝缘体中产生正电荷，导致磁滞（前扫和后扫之间的VT增量）增加。利用提取的态密度（DOS）和拟合模型研究了a-IGZO薄膜中氧空位（VO）的行为。通过在O2环境下的快速热退火（RTA），恢复了伽玛射线辐照导致的电学性能下降，如VT、边界陷阱、尾受体样态（gTA(E)）和浅层供体样态（gSD(E)）的变化。图形抽象

{"title":"Rapid Thermal Annealing under O2 Ambient to Recover the Deterioration by Gamma-Ray Irradiation in a-IGZO TFTs","authors":"Minah Park, Jaewook Yoo, Hongseung Lee, Hyeonjun Song, Soyeon Kim, Seongbin Lim, Seohyeon Park, Jo Hak Jeong, Bongjoong Kim, Kiyoung Lee, Yoon Kyeung Lee, Keun Heo, Jiseok Kwon, Hagyoul Bae","doi":"10.1007/s13391-024-00526-8","DOIUrl":"10.1007/s13391-024-00526-8","url":null,"abstract":"<div><p>Amorphous indium-gallium-zinc-oxide (a-IGZO) has been attracting great attention as a channel material for dynamic random access memory (DRAM) cell transistors due to its superior characteristics including low leakage current, large area deposition, and back-end-of-line (BEOL) compatibility. It should be clearly taken into account that DRAM will also be used in harsh environments such as military surveillance, aerospace, and nuclear power plants. Especially, these situations can cause inevitable and persistent degradation in long-term operations. When the a-IGZO thin film transistors (TFTs) were irradiated by gamma-ray with total doses of 500 Gy, threshold voltage (<i>V</i><sub>T</sub>) was negatively shifted and hysteresis (delta of <i>V</i><sub>T</sub> between forward and backward sweeps) was increased by creating a positive charge in gate insulator. The extracted density-of-states (DOS) and fitted model were employed to investigate the behavior of oxygen vacancy (<i>V</i><sub>O</sub>) in a-IGZO thin film. Electrical performance degraded by gamma-ray irradiation such as changes in <i>V</i><sub>T</sub>, border trap, tail acceptor-like states (<i>g</i><sub>TA</sub>(<i>E</i>)), and shallow donor-like states (<i>g</i><sub>SD</sub>(<i>E</i>)) were recovered through rapid thermal annealing (RTA) under the O<sub>2</sub> ambient.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"111 - 118"},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of Core/Shell WO3/WS2 Heterostructure Nanowires with Negative Photo-Responsiveness 负光响应性WO3/WS2核壳异质结构纳米线的合成

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

Electronic Materials Letters

Pub Date : 2024-10-10 DOI: 10.1007/s13391-024-00524-w

Yu-Jin Song, Changhyeon Yoo, Camellia Schwartzman, Han-Kyun Shin, Hyoung J. Cho, Yeonwoong Jung, Jung Han Kim

WO₃/WS₂ core/shell nanowires were synthesized using a scalable fabrication method by combining wet chemical etching and chemical vapor deposition (CVD). Initially, WO₃ nanowires were formed through wet chemical etching using a potassium hydroxide (KOH) solution, followed by oxidation at 650 °C. These WO₃ nanowires were then sulfurized at 900 °C to form a WS₂ shell, resulting in WO₃/WS₂ core/shell nanowires with diameters ranging from 90 to 370 nm. The synthesized nanowires were characterized using scanning electron microscopy (SEM), Raman, energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and transmission electron microscopy (TEM). The shell is composed of 2D WS₂ layers with uniformly spaced 2D layers as well as the atomically sharp core/shell interface of WO₃/WS₂. Notably, the WO₃/WS₂ heterostructure nanowires exhibited a unique negative photoresponse under visible light (405 nm) illumination. This negative photoresponse highlights the importance of interface engineering in these heterostructures and demonstrates the potential of WO₃/WS₂ core/shell nanowires for applications in photodetectors and other optoelectronic devices.

Graphical Abstract

采用湿法化学蚀刻和化学气相沉积相结合的可扩展制备方法合成了WO3/WS2核/壳纳米线。最初，WO3纳米线是通过氢氧化钾（KOH）溶液的湿化学蚀刻形成的，然后在650°C下氧化。然后在900℃下对WO3纳米线进行硫化，形成WS2外壳，得到直径为90 ~ 370 nm的WO3/WS2核/壳纳米线。采用扫描电子显微镜（SEM）、拉曼光谱（Raman）、能量色散x射线能谱（EDS）、x射线衍射（XRD）和透射电子显微镜（TEM）对合成的纳米线进行了表征。外壳由均匀间隔的二维WS2层和原子锋利的WO3/WS2核壳界面组成。值得注意的是，WO3/WS2异质结构纳米线在可见光（405 nm）照射下表现出独特的负光响应。这种负光响应突出了界面工程在这些异质结构中的重要性，并证明了WO3/WS2核/壳纳米线在光电探测器和其他光电器件中的应用潜力。图形抽象

{"title":"Synthesis of Core/Shell WO3/WS2 Heterostructure Nanowires with Negative Photo-Responsiveness","authors":"Yu-Jin Song, Changhyeon Yoo, Camellia Schwartzman, Han-Kyun Shin, Hyoung J. Cho, Yeonwoong Jung, Jung Han Kim","doi":"10.1007/s13391-024-00524-w","DOIUrl":"10.1007/s13391-024-00524-w","url":null,"abstract":"<div><p>WO<sub>3</sub>/WS<sub>2</sub> core/shell nanowires were synthesized using a scalable fabrication method by combining wet chemical etching and chemical vapor deposition (CVD). Initially, WO<sub>3</sub> nanowires were formed through wet chemical etching using a potassium hydroxide (KOH) solution, followed by oxidation at 650 °C. These WO<sub>3</sub> nanowires were then sulfurized at 900 °C to form a WS<sub>2</sub> shell, resulting in WO<sub>3</sub>/WS<sub>2</sub> core/shell nanowires with diameters ranging from 90 to 370 nm. The synthesized nanowires were characterized using scanning electron microscopy (SEM), Raman, energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and transmission electron microscopy (TEM). The shell is composed of 2D WS<sub>2</sub> layers with uniformly spaced 2D layers as well as the atomically sharp core/shell interface of WO<sub>3</sub>/WS<sub>2</sub>. Notably, the WO<sub>3</sub>/WS<sub>2</sub> heterostructure nanowires exhibited a unique negative photoresponse under visible light (405 nm) illumination. This negative photoresponse highlights the importance of interface engineering in these heterostructures and demonstrates the potential of WO<sub>3</sub>/WS<sub>2</sub> core/shell nanowires for applications in photodetectors and other optoelectronic devices.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"87 - 93"},"PeriodicalIF":2.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of Diffusion Barrier Properties of Ni–Fe and Ni–Fe–W Layer at the Cu/Sn Interface Cu/Sn界面Ni-Fe和Ni-Fe - w层扩散势垒性能比较

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

Electronic Materials Letters

Pub Date : 2024-10-03 DOI: 10.1007/s13391-024-00525-9

Jinyang Liu, Chongyang Li, Yuexiao Liu, Anmin Hu, Ming Li

Bump is a pivotal technology in 3D IC. However, with the reduction in bump size, there is an urgent need for a high-performance barrier layer material to retard the growth of intermetallic compounds (IMCs) at the interface. The study investigated the diffusion barrier properties and mechanical properties of electrodeposited Ni, Ni–15Fe, Ni–44Fe, Ni–42Fe–16W, and Ni–41Fe–28W. Ni–41Fe–28W demonstrated superior barrier properties, with a thickness of 0.42 μm after aging at 150 °C for 720 h. During the early stages of aging, FeSn₂ were formed at the interface, followed by the later generation of blocky Ni₃Sn₄. With a rise in Fe content, the nucleation of Ni₃Sn₄ was suppressed and the wettability and shear strength of the interface were also enhanced. As for Cu/Ni–Fe–W/Sn, a thin layer of FeSn₂ was also formed, and a whitish Ni–Fe–W–Sn layer was developed at the interface. After aging for 720 h, no significant Ni–Sn IMCs were observed. As W content increased, FeSn₂ converted from layered type to island type. The introduction of W significantly inhibited the diffusion of IMCs nucleation at the interface, endowing Ni–Fe–W with excellent barrier properties. Although W reduced the interface wettability, it enhanced shear strength at lower concentrations, with SAC305/Ni–42Fe–16W achieving the highest strength of 34.8 MPa. While as W content increased, the fracture mode shifted from ductile fracture within the solder to mixed ductile–brittle fracture, leading to decrease in interface reliability. This study provided valuable insights for the design of high-performance barrier layers in advanced packaging.

Graphical Abstract

凹凸是3D集成电路中的一项关键技术。然而，随着凹凸尺寸的减小，迫切需要一种高性能的阻挡层材料来阻止界面上金属间化合物（IMCs）的生长。研究了Ni、Ni - 15fe、Ni - 44fe、Ni - 42fe - 16w和Ni - 41fe - 28w的扩散势垒性能和力学性能。在150℃时效720 h后，Ni-41Fe-28W的阻挡层厚度达到0.42 μm。时效初期，界面处形成FeSn2，后期形成块状Ni3Sn4。随着Fe含量的增加，Ni3Sn4的成核受到抑制，界面的润湿性和剪切强度也有所提高。Cu/ Ni-Fe-W /Sn也形成了一层薄薄的FeSn2，在界面处形成了一层白色的Ni-Fe-W - Sn层。时效720 h后，未观察到明显的Ni-Sn IMCs。随着W含量的增加，FeSn2由层状型向岛状型转变。W的引入显著抑制了界面处IMCs形核的扩散，使Ni-Fe-W具有优异的势垒性能。W虽然降低了界面润湿性，但在较低浓度下提高了抗剪强度，SAC305/ Ni-42Fe-16W强度最高，达到34.8 MPa。随着W含量的增加，焊料内部的断裂模式由延性断裂转变为延性-脆性混合断裂，导致界面可靠性降低。该研究为先进封装中高性能阻挡层的设计提供了有价值的见解。图形抽象

{"title":"Comparison of Diffusion Barrier Properties of Ni–Fe and Ni–Fe–W Layer at the Cu/Sn Interface","authors":"Jinyang Liu, Chongyang Li, Yuexiao Liu, Anmin Hu, Ming Li","doi":"10.1007/s13391-024-00525-9","DOIUrl":"10.1007/s13391-024-00525-9","url":null,"abstract":"<div><p>Bump is a pivotal technology in 3D IC. However, with the reduction in bump size, there is an urgent need for a high-performance barrier layer material to retard the growth of intermetallic compounds (IMCs) at the interface. The study investigated the diffusion barrier properties and mechanical properties of electrodeposited Ni, Ni–15Fe, Ni–44Fe, Ni–42Fe–16W, and Ni–41Fe–28W. Ni–41Fe–28W demonstrated superior barrier properties, with a thickness of 0.42 μm after aging at 150 °C for 720 h. During the early stages of aging, FeSn<sub>2</sub> were formed at the interface, followed by the later generation of blocky Ni<sub>3</sub>Sn<sub>4</sub>. With a rise in Fe content, the nucleation of Ni<sub>3</sub>Sn<sub>4</sub> was suppressed and the wettability and shear strength of the interface were also enhanced. As for Cu/Ni–Fe–W/Sn, a thin layer of FeSn<sub>2</sub> was also formed, and a whitish Ni–Fe–W–Sn layer was developed at the interface. After aging for 720 h, no significant Ni–Sn IMCs were observed. As W content increased, FeSn<sub>2</sub> converted from layered type to island type. The introduction of W significantly inhibited the diffusion of IMCs nucleation at the interface, endowing Ni–Fe–W with excellent barrier properties. Although W reduced the interface wettability, it enhanced shear strength at lower concentrations, with SAC305/Ni–42Fe–16W achieving the highest strength of 34.8 MPa. While as W content increased, the fracture mode shifted from ductile fracture within the solder to mixed ductile–brittle fracture, leading to decrease in interface reliability. This study provided valuable insights for the design of high-performance barrier layers in advanced packaging.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"22 - 31"},"PeriodicalIF":2.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermoelectric Characteristics of Bulk Cr2Te3 with Low Lattice Thermal Conductivity 低点阵热导率大块Cr2Te3的热电特性

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

Electronic Materials Letters

Pub Date : 2024-09-25 DOI: 10.1007/s13391-024-00523-x

Donghyun Shin, Hyunji Kim, Joseph Ngugi Kahiu, Samuel Kimani Kihoi, Ho Seong Lee

In this study, we aimed to synthesize bulk Cr₂Te₃ and evaluate its thermoelectric properties. Previously, Cr₂Te₃ with a layered structure has primarily been synthesized in thin film form for studies that focused on its magnetic properties. The intrinsic layered structure of Cr₂Te₃ can contributes to its low lattice thermal conductivity. Our experimental results confirmed the successful synthesis of a homogeneous single-phase specimen and revealed a significantly low lattice thermal conductivity of 0.31 W/mK at 673 K. Additionally, we explored the substitution of titanium and germanium at chromium sites as a method to enhance thermoelectric performance, achieving a notable increase in the power factor.

Graphical Abstract

在这项研究中，我们的目的是合成块状的Cr2Te3，并评估其热电性能。在此之前，层状结构的Cr2Te3主要以薄膜形式合成，主要用于研究其磁性。Cr₂Te₃固有的层状结构有助于其低晶格导热系数。我们的实验结果证实了均匀单相样品的成功合成，并且在673 K时晶格热导率显著降低，为0.31 W/mK。此外，我们探索了钛和锗在铬位点的替代，作为一种提高热电性能的方法，实现了功率因数的显着增加。图形抽象

引用次数: 0

Multi-Functional Molybdenum Oxide Doping to Improve the Electrical Characteristics of Indium Oxide Thin Film Transistors 多功能氧化钼掺杂改善氧化铟薄膜晶体管电特性

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

Electronic Materials Letters

Pub Date : 2024-09-24 DOI: 10.1007/s13391-024-00522-y

Kwan-Jun Heo, Jae-Yun Lee, Gergely Tarsoly, Sung-Jin Kim

This study investigates the utilization of MoO₃ precursors to enhance the electrical properties and stability of In₂O₃ TFTs based on eco-friendly aqueous solutions. Specifically, MoO₃ doped In₂O₃ (Mo-In₂O₃) TFTs were examined in this research. The Mo cation, hydroxide anion, and oxide radical of the MoO₃ precursor provide free electrons to the In₂O₃ thin film, reducing the trap site between the semiconductor interface, the semiconductor and the insulator, and improving the stability of the device by adjusting the oxygen vacancy. To verify the change in the electrical properties of In₂O₃ TFT due to MoO₃ doping, measurements of electron mobility after 30 days confirmed that In₂O₃ TFT electron mobility decreased by more than 80%, whereas Mo-In₂O₃ TFT electron mobility remained stable. PBS and NBS reliability evaluations confirmed that the Vth change of Mo- In₂O₃ TFT was less than that of In₂O₃ TFT. (In₂O₃ TFT PBS: 5.55 V, NBS: 0.33 V, Mo-In₂O₃ TFT PBS: 4.04 V, NBS: 0.10 V). In order to confirm the interface change of In₂O₃ film according to MoO₃ Doping, the difference in surface roughness was measured using an AFM and found to be within 4%. In addition, the doping effect of the active layer was verified through changes in oxygen species in XPS analysis. To demonstrate its application as an active electronic device, a Mo-In₂O₃ TFT based resistance load inverter was evaluated, and the voltage transfer curve and excellent inversion characteristics of the inverter were confirmed under various V_DD conditions.

Graphical Abstract

Kwan-Jun Heo et al., multi-functional molybdenum oxide doping to improve the electrical characteristics of indium oxide thin film transistors

本研究探讨了利用MoO3前驱体来提高基于环保水溶液的In2O3 tft的电学性能和稳定性。具体来说，本研究考察了MoO3掺杂的In2O3 (Mo-In2O3) tft。MoO3前驱体的Mo阳离子、氢氧阴离子和氧化自由基为In2O3薄膜提供了自由电子，减少了半导体界面、半导体与绝缘体之间的陷阱位，并通过调节氧空位来提高器件的稳定性。为了验证MoO3掺杂导致的In2O3 TFT电学性质的变化，30天后的电子迁移率测量证实In2O3 TFT电子迁移率下降了80%以上，而Mo-In2O3 TFT电子迁移率保持稳定。PBS和NBS可靠性评价证实Mo- In2O3 TFT的Vth变化小于In2O3 TFT。（In2O3 TFT PBS: 5.55 V, NBS: 0.33 V, Mo-In2O3 TFT PBS: 4.04 V, NBS: 0.10 V）.为了证实MoO3掺杂后In2O3膜的界面变化，利用原子力显微镜测量了表面粗糙度的差异，发现差异在4%以内。此外，通过XPS分析中氧组分的变化验证了活性层的掺杂作用。为了证明其作为有源电子器件的应用，对基于Mo-In2O3 TFT的电阻负载逆变器进行了评估，并在各种VDD条件下验证了逆变器的电压传递曲线和优异的逆变特性。[图]许宽俊等，多功能氧化钼掺杂改善氧化铟薄膜晶体管的电学特性

{"title":"Multi-Functional Molybdenum Oxide Doping to Improve the Electrical Characteristics of Indium Oxide Thin Film Transistors","authors":"Kwan-Jun Heo, Jae-Yun Lee, Gergely Tarsoly, Sung-Jin Kim","doi":"10.1007/s13391-024-00522-y","DOIUrl":"10.1007/s13391-024-00522-y","url":null,"abstract":"<div><p>This study investigates the utilization of MoO<sub>3</sub> precursors to enhance the electrical properties and stability of In<sub>2</sub>O<sub>3</sub> TFTs based on eco-friendly aqueous solutions. Specifically, MoO<sub>3</sub> doped In<sub>2</sub>O<sub>3</sub> (Mo-In<sub>2</sub>O<sub>3</sub>) TFTs were examined in this research. The Mo cation, hydroxide anion, and oxide radical of the MoO<sub>3</sub> precursor provide free electrons to the In<sub>2</sub>O<sub>3</sub> thin film, reducing the trap site between the semiconductor interface, the semiconductor and the insulator, and improving the stability of the device by adjusting the oxygen vacancy. To verify the change in the electrical properties of In<sub>2</sub>O<sub>3</sub> TFT due to MoO<sub>3</sub> doping, measurements of electron mobility after 30 days confirmed that In<sub>2</sub>O<sub>3</sub> TFT electron mobility decreased by more than 80%, whereas Mo-In<sub>2</sub>O<sub>3</sub> TFT electron mobility remained stable. PBS and NBS reliability evaluations confirmed that the Vth change of Mo- In<sub>2</sub>O<sub>3</sub> TFT was less than that of In<sub>2</sub>O<sub>3</sub> TFT. (In<sub>2</sub>O<sub>3</sub> TFT PBS: 5.55 V, NBS: 0.33 V, Mo-In<sub>2</sub>O<sub>3</sub> TFT PBS: 4.04 V, NBS: 0.10 V). In order to confirm the interface change of In<sub>2</sub>O<sub>3</sub> film according to MoO<sub>3</sub> Doping, the difference in surface roughness was measured using an AFM and found to be within 4%. In addition, the doping effect of the active layer was verified through changes in oxygen species in XPS analysis. To demonstrate its application as an active electronic device, a Mo-In<sub>2</sub>O<sub>3</sub> TFT based resistance load inverter was evaluated, and the voltage transfer curve and excellent inversion characteristics of the inverter were confirmed under various <i>V</i><sub><i>DD</i></sub> conditions.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Kwan-Jun Heo et al., multi-functional molybdenum oxide doping to improve the electrical characteristics of indium oxide thin film transistors</p></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"9 - 21"},"PeriodicalIF":2.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Crystal Domain on Electrical Performance and Bending Durability of Flexible Organic Thin-Film Transistors with diF-TES-ADT Semiconductor 晶域对采用 diF-TES-ADT 半导体的柔性有机薄膜晶体管电气性能和弯曲耐久性的影响

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

Electronic Materials Letters

Pub Date : 2024-09-15 DOI: 10.1007/s13391-024-00519-7

Dongwook Kim, Joel Ndikumana, Hyeonju Lee, Seullee Lee, Youngjun Yun, Jaehoon Park

In this study, we examined the impact of crystal domain on the electrical performance and durability of flexible organic thin-film transistors (OTFTs). To analyze this, we fabricated the OTFTs on a polyimide substrate using 2,8-difluoro-5,11bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) as the organic semiconductor. To examine the influence of the film morphology and crystallinity on the electrical characteristics of OTFTs, we dissolved diF-TES-ADT in chlorobenzene and toluene solvent, annealed it at different temperatures, and then evaluated its electrical performances. The optimum annealing temperature of the diF-TES-ADT OTFTs was determined through the comprehensive analysis of the electrical parameters. The film morphology and crystallinity of organic semiconductor as a function of temperature were examined using the technical measurement analysis such as the atomic force measurement, X-ray diffraction and polarized optic microscopy. Furthermore, we demonstrated the electrical degradation of the device under prolonged bending cycles and observed the effect of bending stress on the electrical performance of OTFTs. The size of the crystalline domain and surface morphology indicated a slower deterioration of OTFT performance with an increase in the number of bending cycles. It was approved that the crystal grain size and morphology of organic semiconductor may not be critical factors determining the electrical performance of OTFTs, however, the electrical durability against bending stress was significantly degraded by these factors. We speculate that the smaller grain sizes and directionally-grown crystalline structure are highly vulnerable to bending stress, resulting in increased occurrence of void cracks and structural defects.

Graphical Abstract

在这项研究中，我们考察了晶域对柔性有机薄膜晶体管（OTFT）的电气性能和耐用性的影响。为此，我们使用 2,8-二氟-5,11-双（三乙基硅烷基）蒽（diF-TES-ADT）作为有机半导体，在聚酰亚胺基底上制作了 OTFT。为了研究薄膜形貌和结晶度对 OTFT 电学特性的影响，我们将 diF-TES-ADT 溶于氯苯和甲苯溶剂中，在不同温度下退火，然后评估其电学性能。通过对电学参数的综合分析，确定了 diF-TES-ADT OTFT 的最佳退火温度。通过原子力测量、X 射线衍射和偏振光显微镜等技术测量分析，研究了有机半导体的薄膜形貌和结晶度随温度的变化。此外，我们还证明了器件在长时间弯曲循环下的电性能衰减，并观察了弯曲应力对 OTFT 电性能的影响。结晶畴的尺寸和表面形态表明，随着弯曲次数的增加，OTFT 的性能劣化速度减慢。研究结果表明，有机半导体的晶体晶粒尺寸和形态可能不是决定 OTFT 电性能的关键因素，但这些因素会显著降低 OTFT 抗弯曲应力的电耐久性。我们推测，较小的晶粒尺寸和定向生长的晶体结构极易受到弯曲应力的影响，导致空隙裂纹和结构缺陷的发生率增加。

{"title":"Impact of Crystal Domain on Electrical Performance and Bending Durability of Flexible Organic Thin-Film Transistors with diF-TES-ADT Semiconductor","authors":"Dongwook Kim, Joel Ndikumana, Hyeonju Lee, Seullee Lee, Youngjun Yun, Jaehoon Park","doi":"10.1007/s13391-024-00519-7","DOIUrl":"10.1007/s13391-024-00519-7","url":null,"abstract":"<div><p>In this study, we examined the impact of crystal domain on the electrical performance and durability of flexible organic thin-film transistors (OTFTs). To analyze this, we fabricated the OTFTs on a polyimide substrate using 2,8-difluoro-5,11bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) as the organic semiconductor. To examine the influence of the film morphology and crystallinity on the electrical characteristics of OTFTs, we dissolved diF-TES-ADT in chlorobenzene and toluene solvent, annealed it at different temperatures, and then evaluated its electrical performances. The optimum annealing temperature of the diF-TES-ADT OTFTs was determined through the comprehensive analysis of the electrical parameters. The film morphology and crystallinity of organic semiconductor as a function of temperature were examined using the technical measurement analysis such as the atomic force measurement, X-ray diffraction and polarized optic microscopy. Furthermore, we demonstrated the electrical degradation of the device under prolonged bending cycles and observed the effect of bending stress on the electrical performance of OTFTs. The size of the crystalline domain and surface morphology indicated a slower deterioration of OTFT performance with an increase in the number of bending cycles. It was approved that the crystal grain size and morphology of organic semiconductor may not be critical factors determining the electrical performance of OTFTs, however, the electrical durability against bending stress was significantly degraded by these factors. We speculate that the smaller grain sizes and directionally-grown crystalline structure are highly vulnerable to bending stress, resulting in increased occurrence of void cracks and structural defects.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"1 - 8"},"PeriodicalIF":2.1,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

All-Cobalt-Free Layered/Olivine Mixed Cathode Material for High-Electrode Density and Enhanced Cycle-Life Performance 全无钴层状/橄榄石混合阴极材料可实现高电极密度和更长的循环寿命性能

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

Electronic Materials Letters

Pub Date : 2024-09-12 DOI: 10.1007/s13391-024-00521-z

Chang-Su Kim, Kookhan Kim, An-Seop Im, Sung-Su Kim, Jongmin Kim, Ji-Yong Eom

In this study, a high-energy-density electrode was fabricated by combining cobalt-free layered oxide (NM) with olivine LiFePO₄ (LFP) nanoparticles. The resulting mixed all-cobalt-free cathode electrode effectively minimized electrode porosity by filling the interstitial spaces between the micron-sized layered-oxide particles with nanoscale LFP particles, significantly improving electrode density, and exhibiting excellent electrode conductivity. Furthermore, the composite electrode composed of NM and LFP achieved a volumetric capacity exceeding 600 mAh/cm^− 3, comparable to that of typical layered oxide cathode materials, while also demonstrating enhanced cycle-life performance relative to electrodes composed solely of layered oxide or LFP. The enhanced electrochemical performance is attributed to the efficient lithium-ion and electron conduction facilitated by the intimate contact between NM and LFP particles, the suppression of NM particle degradation due to the relatively stable LFP particles on the NM surface, and the reduced particle fracture during roll-pressing. These improvements have been confirmed through electrochemical analyses and electrode observations.

Graphical Abstract

在这项研究中，通过将无钴层状氧化物（NM）与橄榄石型磷酸铁锂（LFP）纳米颗粒相结合，制造出了一种高能量密度电极。通过用纳米级 LFP 颗粒填充微米级层状氧化物颗粒之间的间隙，所得到的混合全无钴阴极电极有效地减少了电极孔隙率，显著提高了电极密度，并表现出优异的电极导电性。此外，由 NM 和 LFP 组成的复合电极的体积容量超过了 600 mAh/cm- 3，与典型的层状氧化物阴极材料相当，同时还显示出相对于仅由层状氧化物或 LFP 组成的电极更强的循环寿命性能。电化学性能的提高归功于 NM 和 LFP 颗粒之间的亲密接触促进了锂离子和电子的高效传导，NM 表面相对稳定的 LFP 颗粒抑制了 NM 颗粒的降解，以及辊压过程中颗粒断裂的减少。这些改进已通过电化学分析和电极观察得到证实。

{"title":"All-Cobalt-Free Layered/Olivine Mixed Cathode Material for High-Electrode Density and Enhanced Cycle-Life Performance","authors":"Chang-Su Kim, Kookhan Kim, An-Seop Im, Sung-Su Kim, Jongmin Kim, Ji-Yong Eom","doi":"10.1007/s13391-024-00521-z","DOIUrl":"10.1007/s13391-024-00521-z","url":null,"abstract":"<div><p>In this study, a high-energy-density electrode was fabricated by combining cobalt-free layered oxide (NM) with olivine LiFePO<sub>4</sub> (LFP) nanoparticles. The resulting mixed all-cobalt-free cathode electrode effectively minimized electrode porosity by filling the interstitial spaces between the micron-sized layered-oxide particles with nanoscale LFP particles, significantly improving electrode density, and exhibiting excellent electrode conductivity. Furthermore, the composite electrode composed of NM and LFP achieved a volumetric capacity exceeding 600 mAh/cm<sup>− 3</sup>, comparable to that of typical layered oxide cathode materials, while also demonstrating enhanced cycle-life performance relative to electrodes composed solely of layered oxide or LFP. The enhanced electrochemical performance is attributed to the efficient lithium-ion and electron conduction facilitated by the intimate contact between NM and LFP particles, the suppression of NM particle degradation due to the relatively stable LFP particles on the NM surface, and the reduced particle fracture during roll-pressing. These improvements have been confirmed through electrochemical analyses and electrode observations.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"799 - 806"},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0