Article
Chemistry, Multidisciplinary
Seon Baek Lee, Siyoung Lee, Dae Gun Kim, Seung Hyun Kim, Boseok Kang, Kilwon Cho
Summary: This research presents a new simple bar-coating technique to rapidly and effectively form organic semiconductor thin-film patterns, offering potential breakthroughs in industrial applications in the field of organic electronics.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Yu-Hsuan Su, Wei-Liang Chen, Hye Ryung Byun, Yu-Fu Zhang, Min-Rui Zhuang, Yu-Cih Lin, Chung-Kai Chang, Po-Yuan Wang, Che-Cheng Lin, Kuang- Lin, Hsin-Kuan Liu, Min-Kai Lee, Joon Jang, Yu-Ming Chang, Kuei-Fang Hsu
Summary: A new copper indium selenide with an orthorhombic crystal structure was synthesized at 800 degrees C. It emits intense photoluminescence at 657 nm and exhibits a direct band gap with an energy close to the photoluminescence position. The compound also shows n-type conductivity and strong nonlinear third-harmonic generation.
INORGANIC CHEMISTRY
(2023)
Article
Nanoscience & Nanotechnology
Naoki Higashitarumizu, Shiekh Zia Uddin, Daniel Weinberg, Nima Sefidmooye Azar, I. K. M. Reaz Rahman, Vivian Wang, Kenneth B. B. Crozier, Eran Rabani, Ali Javey
Summary: The photophysics of black phosphorus, an optoelectronic material, was investigated. It was found that the photoluminescence quantum yield initially decreases with decreasing thickness due to enhanced surface carrier recombination, but sharply increases afterwards. Furthermore, black phosphorus exhibits a much lower surface carrier recombination velocity compared to other semiconductors.
NATURE NANOTECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
[Anonymous]
Summary: Authors are requested to submit unpublished manuscripts for inclusion in an upcoming event.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Tonglin L. Newsom, Christopher R. Allemang, Tae H. Cho, Neil P. Dasgupta, Rebecca L. Peterson
Summary: By depositing both ZTO channel and Al2O3 gate dielectric layer using ALD without breaking vacuum, we achieved TFTs with a steep SS of 59.9mV center dot dec(-1), close to the Boltzmann limit at room temperature. The measured SS value extracted an extremely low interface trap density of 9.59 x 10(9) cm(-2)eV(-1), which was corroborated by the high-low frequency capacitance method. Compared with other TFT processes, both higher-k gate dielectric and in situ ALD process are required to obtain the low SS value. The TFT made with in situ dielectric deposition demonstrated a maximum linear mobility of 19.2 cm(2)V(-1)s(-1), an ON/OFF current ratio > 10(8), and a threshold voltage of 1.3 V. The achieved sharp SS will enable low voltage electronics using this scalable ALD technology.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Aimi Syairah Safaruddin, Juan Paolo S. Bermundo, Michael Paul A. Jallorina, Atsuko Yamamoto, Yukiharu Uraoka
Summary: The reliability of solution-processed amorphous indium zinc oxide (a-IZO) thin-film transistors (TFTs) was evaluated using inorganic-organic fluorinated polysilsesquioxane (PSQ:F) passivation layers. The PSQ:F passivation layers exhibited superior barrier property and improved the stability and electrical performance of the devices.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Jiangnan Xia, Xincan Qiu, Yu Liu, Ping-An Chen, Jing Guo, Huan Wei, Jiaqi Ding, Haihong Xie, Yawei Lv, Fuxiang Li, Wenwu Li, Lei Liao, Yuanyuan Hu
Summary: A general device fabrication strategy for metal halide perovskite (MHP) FETs is proposed, which successfully obtains transparent perovskite FETs. The strategy involves the use of ferroelectric copolymer poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) as the dielectric, which solves the challenging issue of gate-electric-field screening effect in MHP FETs. Additionally, ultra-thin SnO2 is inserted between the source/drain electrodes and MHPs to facilitate electron injection. These FETs have the attractiveness of low-cost, large-area transparent electronics applications.
Article
Engineering, Electrical & Electronic
Zhiqiang Mu, Hongyang Zhou, Yumeng Yang, Qiang Liu, Xing Wei, Wenjie Yu
Summary: A novel junctionless gate-all-around (GAA) transistor with ultrathin nanosheet GAA channel and self-aligned raised source/drain (RSD) was successfully designed and fabricated on void embedded silicon on insulator (VESOI) substrate using a simpler fabrication process. Devices with a channel thickness as thin as 13 nm exhibited excellent electrical characteristics, with an on/off current ratio of 10(6) and an on-state drive current of 58 μA/μm. Despite the presence of parasitic planar channel component, the device performance was predominantly determined by the GAA channel, which was further enhanced by the junction-free bulk conduction mechanism and the self-aligned RSD structure.
ELECTRONICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Alexandre Bachelet, Sophie Fasquel, Jean-Michel Rampnoux, Gediminas Jonusauskas, Kazuo Takimiya, Lionel Hirsch, Mathias Perrin, Mamatimin Abbas
Summary: Using a single emissive layer, this study achieved color tuning within a wide visible light range (from blue to red) in organic light emitting transistors. The color tuning does not affect the optical turn-on voltages and significantly enhanced external quantum efficiencies are observed for devices with a thick emissive layer. The wide range of color tunability is mainly due to an outcoupling effect through the Fabry-Perot cavity.
Article
Chemistry, Physical
Wenjing Qi, Jiale Li, Peng Wang, Hao Ling, Xinpeng Zhang, Xiangyu Li, Lei Tao, Xue Fu, Khumal Sohail, Linchuan Ma, Jingshan Luo, Yuelong Li
Summary: The controlled crystallization process is crucial for the morphological quality of wide-band-gap perovskite absorbers, especially with excessive bromide ions. Surface defects and non-radiative recombination are major obstacles for highly efficient wide-band-gap perovskite solar cells (PSCs). In this study, 1.65 eV wide-band-gap PSCs were fabricated using a sequential deposition method, resulting in highly reproducible perovskite absorbers with tailored morphology. The addition of NH4Cl facilitated controlled crystallization, leading to larger and more uniform grains and fewer bulk defects. Furthermore, (NH4)2SO4 as a passivation layer reduced surface defects and improved hydrophobicity. The synergistic effect of ammonium salts resulted in a high V_OC of 1.18 V and an optimal efficiency of 20.43% for 1.65 eV wide-band-gap PSCs constructed by a two-step deposition process. These findings highlight the effectiveness of the sequential deposition method and the use of proper ammonium salts for highly efficient and stable wide-band-gap PSCs.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Daniel M. Dryden, Kyle J. Liddy, Ahmad E. Islam, Jeremiah C. Williams, Dennis E. Walker, Nolan S. Hendricks, Neil A. Moser, Andrea Arias-Purdue, Nicholas P. Sepelak, Kursti DeLello, Kelson D. Chabak, Andrew J. Green
Summary: We demonstrate a passivated MESFET fabricated on (010) Si-doped beta-Ga2O3 with breakdown over 2.4 kV without field plates, high Power Figure of Merit (PFOM), and high estimated Huang's Material Figure of Merit (HMFOM), owing to low gate charge and high breakdown. MESFETs with 13 μm source-drain spacing and 75 nm channel exhibited a current density of 61 mA/mm, peak transconductance of 27 mS/mm, and on-resistance of 133 Ω•mm. The device showed a PFOM competitive with state-of-the-art beta-Ga2O3 devices and a record high estimated HMFOM for a beta-Ga2O3 device, competitive with commercial wide-band gap devices. This demonstrates high-performance beta-Ga2O3 devices as viable multi-kV high-voltage power switches.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Sheng-Yao Chou, Pei-Yu Wu, Ming-Chen Chen, Ting-Chang Chang, Xin-Ying Tsai, Shih-Kai Lin, Ting-Tzu Kuo, Wei-Chen Huang, Hong-Yi Tu, Chung-Wei Wu, Tsung-Ming Tsai, Jen-Wei Huang
Summary: In this study, a supercritical oxygen treatment method is proposed to eliminate the defects of enhancement-mode p-GaN high-electron mobility transistors. The treatment improves the ON-state current and transconductance of the device without changing the threshold voltage. The statistical analysis shows an improvement in device uniformity after the treatment. Gate lag and pulsed I_D - V_D measurements are used to examine the interface between the passivation layer and the AlGaN layer.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Multidisciplinary
Yuqi Wei, Md Maksudul Hossain, H. Alan Mantooth
Summary: In this article, the static and dynamic characterizations of semiconductors with different materials at room temperature and cryogenic temperature are evaluated and compared. The results show that silicon and gallium nitride-based semiconductors have improved performances at low temperature, while silicon carbide-based semiconductors exhibit reduced performance. These evaluation results can guide cryogenic power electronics applications and future semiconductor characterization research.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Abdul Ghaffar, Mohit D. Ganeriwala, Kenta Hongo, Ryo Maezono, Nihar R. Mohapatra
Summary: A systematic ab initio study of metal-phosphorene interfaces was conducted using DFT, involving 18 potentially suitable metals with different resistivity, electronegativity, and work function. The mechanical and electrical behavior of metal contacts with phosphorene were analyzed, with factors such as work of separation, Schottky barrier height, and mid-interface charge density being considered. The interface chemistry was found to play a key role in determining the performance of the metal contacts.
Review
Chemistry, Multidisciplinary
Xiaochi Liu, Min Sup Choi, Euyheon Hwang, Won Jong Yoo, Jian Sun
Summary: This article discusses the impact of Fermi level pinning (FLP) in 2D semiconductor devices and its causes. The authors indicate that FLP is mainly due to inefficient doping into 2D materials, vdW gap at the metal interface, and hybridized compounds formed under contacting metals. The article further explores the effects of FLP on 2D device performance and methods for improving metallic contact to 2D materials.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Simon Schweidler, Henrik Schopmans, Patrick Reiser, Evgeniy Boltynjuk, Jhon Jairo Olaya, Surya Abhishek Singaraju, Franz Fischer, Horst Hahn, Pascal Friederich, Leonardo Velasco
Summary: High-entropy alloys offer a wide research area for new material compositions and applications. A high-throughput magnetron sputtering synthesis method is presented to fabricate a new HEA gradient layer, allowing for the study of the composition of the HEA system and the influence of individual elements on material properties.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Alexander D. Dupuy, Mohammed Reda Chellali, Horst Hahn, Julie M. Schoenung
Summary: The formation mechanisms of Cu-rich and Co-rich secondary phases in rocksalt-structured entropy-stabilized oxides were studied. It was found that these secondary phases do not nucleate directly, but first form precursor phases rich in Cu and Co, respectively, and then undergo structural transformations. The growth of secondary phases is controlled by cation diffusion within the primary phase.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Yemao Lu, Horst Hahn, Yulia Ivanisenko
Summary: In this study, a CoCrFeMnNi high-entropy alloy with reduced Cr content and the addition of 2 at% C interstitial was processed via high-pressure torsion. The results show that C atoms segregate at the boundaries of nanograins in the sample processed at room temperature, while no notable segregations of carbon were observed in the sample processed at cryogenic temperature.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Abhishek Sarkar, Di Wang, Mohana Kante, Luis Eiselt, Vanessa Trouillet, Gleb Iankevich, Zhibo Zhao, Subramshu S. Bhattacharya, Horst Hahn, Robert Kruk
Summary: Technologically relevant strongly correlated phenomena exhibited by perovskite manganites are enhanced by the coexistence of multiple competing magneto-electronic phases. The recently discovered high entropy oxides exhibit indications of an inherent magneto-electronic phase separation encapsulated in a single crystallographic phase. Combining the high entropy concept with standard property control, the study demonstrates the potential for a synergetic development of strongly correlated oxides offered by the high entropy design approach.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Gleb Iankevich, Abhishek Sarkar, Shyam Katnagallu, Mohammed Reda Chellali, Di Wang, Leonardo Velasco, Ruby Singh, Thomas Reisinger, Robert Kruk, Horst Hahn
Summary: Nanocomposite materials, with the ability to tailor their structural properties and functionalities, play a unique role in materials science. This study demonstrates the possibility of achieving nanocomposites from a bimetallic system, which overcomes the limitations of thermodynamic stability conditions. By co-depositing 2000-atom Ni-clusters and Cu-atoms, nanocomposite samples with different compositions are synthesized. The retention of the metastable nanostructure is confirmed through various characterization techniques. The magnetic properties of the nanocomposites can be tailored by controlling the Ni concentration, offering a promising direction for future research on nanocomposites consisting of fully miscible elements.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
A. Sharma, A. Tripathi, Sree Harsha Nandam, Horst Hahn, K. Eswar Prasad
Summary: Nanoindentation experiments were conducted on a binary Pd-Si metallic glass (MG) and nanoglass (NG) using different indenters to study the effect of indenter geometry on the deformation behavior. It was found that the cube-corner indenter resulted in more pop-ins and higher pile-up compared to the Berkovich indenter. The NG displayed lower hardness than the MG, and the hardness decreased with indentation load. The deformation mode was found to be independent of indenter geometry for both glasses.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Editorial Material
Nanoscience & Nanotechnology
Anatolie S. Sidorenko, Horst Hahn, Vladimir Krasnov
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Mohana Kante, Moritz L. Weber, Shu Ni, Iris C. G. van den Bosch, Emma van der Minne, Lisa Heymann, Lorenz J. Falling, Nicolas Gauquelin, Martina Tsvetanova, Daniel M. Cunha, Gertjan Koster, Felix Gunkel, Slavomir Nemsak, Horst Hahn, Leonardo Velasco Estrada, Christoph Baeumer
Summary: High-entropy materials show promise as high-activity catalysts for electrochemical energy storage due to their tunability and multiple potential active sites. This study examines the catalytic activity of high-entropy perovskite oxides (HEOs) for the oxygen evolution reaction (OER) and finds that HEOs outperform their parent compounds by a factor of 17 to 680. X-ray photoemission studies suggest that simultaneous oxidation and reduction of different transition metal cations contribute to the high activity of HEOs.
Article
Materials Science, Ceramics
F. A. Orjuela, F. F. Vallejo, H. Hahn, J. J. Olaya, J. E. Alfonso, L. Velasco
Summary: AlCrTiN coatings were deposited on aluminum-silicon alloy substrates using RF magnetron sputtering. The coatings exhibited a hexagonal Wurtzite structure with preferential growth on the (002) direction. Increasing nitrogen flow resulted in a decrease in crystallite size. The coatings showed improved hardness, wear resistance, and fracture toughness compared to the uncoated substrate.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Shabnam Taheriniya, Nuri Choi, Sangsun Yang, Reshma Sonkusare, Ji Hun Yu, Jai -Sung Lee, Harald Roesner, Martin Peterlechner, Torben Boll, Christoph Gammer, Horst Hahn, Sergiy V. Divinski, Gerhard Wilde
Summary: Additive manufacturing using selective laser melting was used to fabricate a CoCrFeMnNi high-entropy alloy. Analysis techniques such as transmission electron microscopy, nanobeam diffraction, atom probe tomography, and nanoindentation were employed to study the evolution of microstructure and nano-hardness upon annealing. A complex mechano-chemical coupling was observed, leading to segregation and phase separation at grain boundaries. The 3D-printed alloy exhibited increased and homogenized hardness due to the synergetic effects of segregation, nano-precipitation, and dislocation accumulation at high-angle grain boundaries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Mohana Kante, Horst Hahn, Subramshu S. Bhattacharya, Leonardo Velasco
Summary: High entropy oxides (HEOs), a new class of materials, have attracted a lot of attention due to their interesting optical, electrochemical, magnetic, and catalytic properties. To understand the complex interactions in these materials, it is important to evaluate them in dense forms, such as pellets or thin films. In this study, dense films of fluorite structured (CeLaSmPrY)O2-x have been synthesized using sol-gel and pulsed laser deposition processes, showing different microstructural characteristics. This research provides a foundation for comprehensive studies and possible applications of dense fluorite (CeLaSmPrY)O2-x films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Zhenfei Jiang, Weiping Chen, Chenliang Chu, Zhiqiang Fu, Julia Ivanisenko, Hao Wang, Siyuan Peng, Yemao Lu, Enrique J. Lavernia, Horst Hahn
Summary: We report a novel low-cost FeNi0.9Cr0.5Al0.4 high entropy alloy with a unique fibrous heterogeneous solidification microstructure, which consists of fibers-like face-centered-cubic soft phases enveloped in nano-sized ordered body-centered-cubic hard shells. The fibrous microstructure is responsible for its notable mechanical properties, including a yield strength of -670 MPa, an ultimate tensile strength of -1196 MPa, and a uniform elongation of -21.1% at room temperature. The combination of high strength and good ductility is attributed to the hetero-deformation induced hardening mechanism generated from the soft-fiber and hard-shell interface. The cost-effectiveness and outstanding tensile properties make this as-cast FeNi0.9Cr0.5Al0.4 alloy an ideal candidate for structural applications.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Mukesh Kumbhakar, Anurag Khandelwal, Shikhar Krishn Jha, Monaha Veerraju Kante, Pirmin Kessler, Uli Lemmer, Horst Hahn, Jasmin Aghassi-Hagmann, Alexander Colsmann, Ben Breitung, Leonardo Velasco, Simon Schweidler
Summary: High-throughput synthesis and characterization techniques are increasingly important for complex materials and advanced functional compounds. This study focuses on the compilation of high-entropy oxide material libraries with tunable band gaps for semiconductor applications. The material libraries include rare-earth oxides with 5, 6, and 7 different cations in near equimolar concentrations, as well as medium entropy ranges. The atmosphere used during synthesis affects the band gap, and multivalent rare-earth cations enable reversible tuning of the band gap between 2.0 and 3.5 eV under different atmospheres.
ADVANCED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Hendrik Voigt, Aaron Rigoni, Evgeniy Boltynjuk, Harald Roesner, Horst Hahn, Gerhard Wilde
Summary: The crystallization processes of glass-glass interfaces in sputtered CuZr thin film nanoglasses were directly studied using in situ heating experiments in a transmission electron microscope (TEM). By combining in situ technique with symmetry analysis and electron correlation microscopy, correlations between excess volume and nucleation kinetics were obtained on a microscopic scale. It was found that glass-glass interfaces with increased excess volume promoted the onset of crystal nucleation.
MATERIALS RESEARCH LETTERS
(2023)
Article
Chemistry, Physical
Ling Lin, Ziming Ding, Guruprakash Karkera, Thomas Diemant, Mohana V. V. Kante, Daisy Agrawal, Horst Hahn, Jasmin Aghassi-Hagmann, Maximilian Fichtner, Ben Breitung, Simon Schweidler
Summary: High-entropy sulfides (HESs), as a newly developed class of materials, show great potential as efficient electrocatalysts for various reactions. In this study, HESs containing five or six transition metals are synthesized using a one-step mechanochemical process. By comparing the performances and properties of HESs with different compositions and structures with commercial IrO2, it is found that most of the HESs exhibit excellent electrocatalytic performance for the oxygen evolution reaction (OER) under alkaline conditions, outperforming the reference catalyst IrO2.
