Article
Chemistry, Multidisciplinary
Lutz Baumgarten, Thomas Szyjka, Terence Mittmann, Andrei Gloskovskii, Christoph Schlueter, Thomas Mikolajick, Uwe Schroeder, Martina Mueller
Summary: The reliability of ferroelectric HfO2- and HZO-based memory devices is strongly influenced by the choice of electrode materials. Interface conditions, such as band alignment, defect formation, and doping, are recognized as decisive factors for device performance. Hard X-ray photoelectron spectroscopy reveals two opposite scenarios of band alignment in TiN/HZO/TiN and IrO2/HZO/IrO2, explaining the conditions for stable device performance and degradation. A key condition for the stability of ferroelectric devices is identified as the alignment of the charge neutrality level with the metallic Fermi level. Oxygen-deficient HfO2-based interfaces, where the Fermi level of the metal electrode is close to the conduction band of the ferroelectric insulator, can achieve stable device performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Weijie Zhao, Mats Gothelid, Saman Hosseinpour, Malin B. Johansson, Gen Li, Christofer Leygraf, C. Magnus Johnson
Summary: The adsorption of octadecylphosphonic acid (ODPA) on copper substrates was studied, showing that a multilayer film was formed with increasing deposition time. The robustness of the film was attributed to the formation of Cu-ODPA complexes. Preadsorbing a monolayer of octadecylthiol (ODT) prevented the adsorption of ODPA by abolishing the release of Cu(I) ions.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Physical
Krystyna Mika, Ewelina Wiercigroch, Marcin Pisarek, Marcin Koziel, Dorota Majda, Anton S. Lytvynenko, Grzegorz D. Sulka, Leszek Zaraska
Summary: This study demonstrates the electrochemical generation of nanowire arrays via one-step anodic oxidation of Zn in carbonate-based electrolytes with different pH values. The morphology of the anodic films was characterized, and the composition of the nanomaterials was analyzed using various techniques. The formation of a previously unknown phase of zinc carbonate and the generation of ZnO were observed during the anodization process. The changes occurring during thermal treatment and the photoelectrochemical performance of the ZnO nanostructures were also investigated.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Angelo Tricase, Anna Imbriano, Nicoletta Ditaranto, Eleonora Macchia, Rosaria Anna Picca, Davide Blasi, Luisa Torsi, Paolo Bollella
Summary: This study combines electrochemical and XPS experiments to investigate the conformational rearrangement of self-assembled monolayers (SAMs) on an electrode surface due to the application of an electrical field. It was found that activation and deactivation processes play a crucial role in reaction yields and conformational rearrangement, ultimately impacting the performance of bioelectronic devices.
Article
Chemistry, Multidisciplinary
Alex Henning, Johannes D. Bartl, Andreas Zeidler, Simon Qian, Oliver Bienek, Chang-Ming Jiang, Claudia Paulus, Bernhard Rieger, Martin Stutzmann, Ian D. Sharp
Summary: Atomic layer deposition (ALD) is a crucial tool in semiconductor device fabrication for precise control over thin film growth. However, challenges in creating continuous monolayers exist due to surface inhomogeneities and precursor steric interactions. This study demonstrates the encapsulation of c-plane gallium nitride with extremely thin aluminum oxide through ALD, offering new possibilities for controlling charge transport and tailoring surface chemistry in semiconductor devices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Indrajit V. Bagal, Pratik Mane, Maheshwari Arunachalam, Hyojung Bae, Mandar A. Kulkarni, Fawad Tariq, Soon Hyung Kang, Jun-Seok Ha, Sang-Wan Ryu
Summary: By constructing a type-II heterostructure of N-doped ZnO nanowires with an ultra-thin ZnS layer, a core-shell structure is formed which can accelerate the charge transfer process and significantly enhance the resistance to photo-corrosion of N-doped ZnO NWs. The optimal ZnS/N:ZnO core-shell nanowires exhibited a photocurrent density of 0.85 mA cm(-2) at 1.23 Vs RHE, which was 3-fold higher than ZnO nanowires. The reported approach provides possibilities for the construction of efficient and highly stable PEC water-splitting devices.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Physical
Kexin Li, Mouhui Yan, Yukun Jin, Yichen Jin, Yefei Guo, Elena Voloshina, Yuriy Dedkov
Summary: The electronic structure of the alloyed transition-metal phosphorus trichalcogenide van der Waals Fe1-xNixPS3 compounds is studied. The Fe-and Ni-ions-derived electronic states are highly localized, leading to the description of the spectroscopic data as belonging simultaneously to Mott-Hubbard and charge-transfer insulators. These findings highlight the unique layered compounds Fe1-xNixPS3 with dual character, emphasizing their importance for understanding the functionality of this class of materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Koji Abe
Summary: The influence of the reaction between water and ZnO on the properties of Au Schottky contacts and the photocatalytic activity of Zn-face ZnO(0001) single crystals was investigated. Water treatment changed the properties of Au contacts but had no significant influence on the photocatalytic activity of ZnO substrate.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Chemistry, Multidisciplinary
Jiangyang Liu, Kazuki Nagashima, Yuki Nagamatsu, Takuro Hosomi, Hikaru Saito, Chen Wang, Wataru Mizukami, Guozhu Zhang, Benjarong Samransuksamer, Tsunaki Takahashi, Masaki Kanai, Takao Yasui, Yoshinobu Baba, Takeshi Yanagida
Summary: The surface cation composition of nanoscale metal oxides plays a critical role in determining the properties of various chemical processes, such as catalysts and molecular sensors. This study focused on the modulation of cation composition on the surface of ZnO/(Cu1-xZnx)O heterostructured nanowires and found that an increase in surface copper content suppresses the adsorption of nonanal and the aldol condensation reaction. Spectroscopic analysis and theoretical simulations revealed that surface Cu2+ sites were inactive, explaining the observed weak molecular adsorption behaviors and suppressed reactions. This tailored cation composition surface also showed improvements in electrical molecular sensing of nonanal.
Article
Nanoscience & Nanotechnology
Sol Kim, R. M. Dulanga S. Somaratne, Owen C. Grimm, Diane M. Steeves, Jason W. Soares, Richard Pang, Elizabeth A. Welsh, James E. Whitten
Summary: A simple method has been developed to functionalize polypropylene surfaces with metal oxide nanoparticles, providing a new approach for the catalysis/photocatalysis applications of fibers and fabrics.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Igor A. Pronin, Igor A. Averin, Andrey A. Karmanov, Nadezhda D. Yakushova, Alexey S. Komolov, Eleonora F. Lazneva, Maxim M. Sychev, Vyacheslav A. Moshnikov, Ghenadii Korotcenkov
Summary: The surface properties of zinc oxide powders prepared using mechanical activation, electron beam irradiation, and vacuum annealing were studied. These treatments were found to have an impact on the size of nanocrystals, microdeformations, formation of vacancies, and diffusion of zinc ions. X-ray diffraction and scanning electron microscopy were used to analyze the structure of the obtained materials.
Article
Chemistry, Multidisciplinary
Shi Li, Hongru Zhang, Zheng Liu, Junquan Xu, Guofang Fan, Wei Li, Qi Li, Xiaodong Hu, Gaoshan Jing
Summary: Developing new metrology techniques is crucial in semiconductor fabrication to accurately measure film thickness and material properties. Highly uniform FDTS SAM film patterns were fabricated using conventional methods and investigated using AES and XPS techniques.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Ya-Hsiang Liang, Saravanan Kumaran, Michael Zharnikov, Yian Tai
Summary: Top gate thin film transistors using solution processes can reduce fabrication costs, but may result in gate leakage. Engineering the IGZO/insulator interface with self-assembled monolayers can effectively reduce leakage current in TFTs.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Xintai Wang, Ali Ismael, Shanglong Ning, Hanan Althobaiti, Alaa Al-Jobory, Jan Girovsky, Hippolyte P. A. G. Astier, Luke J. O'Driscoll, Martin R. Bryce, Colin J. Lambert, Christopher J. B. Ford
Summary: This study investigates the effect of the molecule-electrode interface in SAMs using a micro-pore device, overcoming challenges with the tetrapodal anchor and single layered graphene top electrode with an ionic liquid gate. Experimental results show that molecules with the same backbone but different molecule-electrode interfaces exhibit significantly different conductances near zero bias.
NANOSCALE HORIZONS
(2022)
Article
Materials Science, Multidisciplinary
K. Soumya, I. Packia Selvam, C. P. Vinod, S. N. Potty
Summary: Using X-ray photoelectron spectroscopy, the shift in the work function of ZnO thin film upon varying codoping ratio was investigated. A notable shift of 0.2 eV in the work function was observed when the Al: In doping ratio was changed. XPS analysis showed higher concentration of In dopant compared to Al in the codoped ZnO films. The study also found a decrease in work function with increasing free carrier concentration when the codopant ratio is changed.
Article
Chemistry, Multidisciplinary
Hatem Brahmi, Giwan Katwal, Mohammad Khodadadi, Shuo Chen, Maggie Paulose, Oomman K. Varghese, Anastassios Mavrokefalos
Article
Engineering, Electrical & Electronic
Seung Hwan Kim, Shivkant Singh, Seung Kyu Oh, Dong Kyu Lee, Keon Hwa Lee, Shahab Shervin, Mojtaba Asadirad, Venkat Venkateswaran, Kathy Olenick, John A. Olenick, Sung-Nam Lee, Joon Seop Kwak, Anastassios Mavrokefalos, Jae-Hyun Ryou
IEEE ELECTRON DEVICE LETTERS
(2016)
Article
Physics, Applied
Hatem Brahmi, Srikanth Ravipati, Milad Yarali, Shahab Shervin, Weijie Wang, Jae-Hyun Ryou, Anastassios Mavrokefalos
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2017)
Article
Chemistry, Multidisciplinary
Milad Yarali, Ji Hao, Mohammad Khodadadi, Hatem Brahmi, Shuo Chen, Viktor G. Hadjiev, Yung Joon Jung, Anastassios Mavrokefalos
Article
Nanoscience & Nanotechnology
Milad Yarali, Hatem Brahmi, Zhequan Yan, Xufan Li, Lixin Xie, Shuo Chen, Satish Kumar, Mina Yoon, Kai Xiao, Anastassios Mavrokefalos
ACS APPLIED MATERIALS & INTERFACES
(2018)
Article
Nanoscience & Nanotechnology
Shivkant Singh, Shahab Shervin, Haiding Sun, Milad Yarali, Jie Chen, Ronghui Lin, Kuang-Hui Li, Xiaohang Li, Jae-Hyun Ryou, Anastassios Mavrokefalos
ACS APPLIED MATERIALS & INTERFACES
(2018)
Article
Physics, Applied
Anastassios Mavrokefalos, Qiyin Lin, Matthew Beekman, Jae Hun Seol, Yong J. Lee, Huijun Kong, Michael T. Pettes, David C. Johnson, Li Shi
APPLIED PHYSICS LETTERS
(2010)
Article
Physics, Applied
Sheng Shen, Anastassios Mavrokefalos, Poetro Sambegoro, Gang Chen
APPLIED PHYSICS LETTERS
(2012)
Article
Chemistry, Physical
Ngoc T. Nguyen, Polly A. Berseth, Qiyin Lin, Catalin Chiritescu, David G. Cahill, Anastassios Mavrokefalos, Li Shi, Paul Zschack, Michael D. Anderson, Ian M. Anderson, David C. Johnson
CHEMISTRY OF MATERIALS
(2010)
Article
Physics, Applied
Anastassios Mavrokefalos, Arden L. Moore, Michael T. Pettes, Li Shi, Wei Wang, Xiaoguang Li
JOURNAL OF APPLIED PHYSICS
(2009)
Article
Chemistry, Multidisciplinary
Anastassios Mavrokefalos, Sang Eon Han, Selcuk Yerci, Matthew S. Branham, Gang Chen
Article
Chemistry, Multidisciplinary
Hatem Brahmi, Ram Neupane, Lixin Xie, Shivkant Singh, Milad Yarali, Giwan Katwal, Shuo Chen, Maggie Paulose, Oomman K. Varghese, Anastassios Mavrokefalos
Article
Nanoscience & Nanotechnology
S. Singh, P. Dutta, M. Rathi, Y. Yao, Y. Gao, S. Sun, D. Khatiwada, V. Selvamanickam, A. Mavrokefalos
Article
Chemistry, Multidisciplinary
Milad Yarali, Xufei Wu, Tushar Gupta, Debjit Ghoshal, Lixin Xie, Zhuan Zhu, Hatem Brahmi, Jiming Bao, Shuo Chen, Tengfei Luo, Nikhil Koratkar, Anastassios Mavrokefalos
ADVANCED FUNCTIONAL MATERIALS
(2017)
Article
Chemistry, Multidisciplinary
Guodong Li, Milad Yarali, Alexandr Cocemasov, Stefan Baunack, Denis L. Nika, Vladimir M. Fomin, Shivkant Singh, Thomas Gemming, Feng Zhu, Anastassios Mavrokefalos, Oliver G. Schmidt