Article
Biochemical Research Methods
Abdullah Abdulhameed, Mohd Nazim Mohtar, Mohd Nizar Hamidon, Izhal Abdul Halin
Summary: The study validates a novel DEP setup that reduces the medium drag velocity by using a top glass cover, addressing issues with CNT assembly on large-scale electrode structures. Experimental results show successful assembly and alignment of CNT bridges on ITO electrodes, along with deriving an equation for optimizing CNT concentration. The deposition of long CNTs on ITO electrodes has potential applications in transparent electronics and microfluidic systems.
Article
Chemistry, Multidisciplinary
Masaru Irita, Takahiro Yamamoto, Yoshikazu Homma
Summary: The study used photoluminescence spectroscopy to directly measure the chirality distributions of individual semiconducting SWCNTs, confirming the influence of chiral angles on the growth yield. When higher-yield chiralities are selected, the chiral angle distribution fits well with a model that incorporates the thermodynamic effect. These quantitative and statistical data provide new insights into the SWCNT growth mechanism and validate theoretical predictions.
Review
Chemistry, Multidisciplinary
Jaehyoung Ko, Yongho Joo
Summary: The development of sorting techniques for SWCNTs has led to the replacement of unsorted SWCNTs with electronically enriched SWCNTs in various applications to improve device performance. While research has focused on semiconducting SWCNTs, the potential of metallic SWCNTs has been largely disregarded despite their exceptional properties that complement those of semiconducting SWCNTs. A comprehensive review of research on metallic SWCNTs in the past decade is necessary to highlight their role in various applications.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Abdullah Abdulhameed, Mohd Nazim Mohtar, Mohd Nizar Hamidon, Ishak Mansor, Izhal Abdul Halin
Summary: In this study, multi-walled carbon nanotubes were aligned across ITO electrodes separated by 50 μm to form a conductive network. The alignment was improved with increasing frequency (>10(5) Hz) and the deposition process was monitored in real-time using optical microscopy and FeSEM spectroscopy. The study also investigated the resistivity, density, and length of the aligned MWCNTs as a function of time.
MICROELECTRONIC ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Dan Zhao, Rui Liu, Cheng Luo, Yang Guo, Chengyi Hou, Qinghong Zhang, Yaogang Li, Wei Jia, Hongzhi Wang
Summary: The study focuses on the in-situ assembly of carbon nanotubes (CNTs) using macroscopic dielectrophoresis, overcoming the limitation of small size in traditional manipulation methods. Through optimizing voltage and frequency, ordered CNTs chains can be obtained under the action of alternating current dielectrophoresis, which can restore immediately upon powering up after being damaged. Different conductive patterns on non-woven fabric can be achieved by controlling the position of the electrodes in a wet environment.
ADVANCED FIBER MATERIALS
(2021)
Review
Nanoscience & Nanotechnology
Abdullah Abdulhameed, Mohd Mahadi Halim, Izhal Abdul Halin
Summary: Carbon nanotubes (CNTs) are potential successors to semiconductors and metals due to their unique properties, but their anisotropy and low controllability hinder their commercial applications. Dielectrophoresis (DEP) is an electrokinetic motion of polarizable nanoparticles in nonuniform electric fields, which can be used to align, assemble, separate, and manipulate CNTs suspended in liquid mediums. This article provides an overview of CNT structure, production, and their response to electric fields, explores the DEP phenomenon as a CNT alignment method, discusses side forces in DEP systems, and reviews CNT-based devices fabricated using DEP, as well as its limitations and future prospects.
Article
Engineering, Electrical & Electronic
Abdullah Abdulhameed, Izhal Abdul Halin, Mohd Nazim Mohtar, Mohd Nizar Hamidon
Summary: This study investigates the effects of electrode geometry on the dielectrophoretic assembly of multi-walled carbon nanotube bundles. A computational model is used to predict the motion and assembly location of the bundles, and experimental work is conducted to validate the simulation results. The density and shape of the assembled bundles are controlled by optimizing the electrode dimensions and adjusting the AC signal parameters.
JOURNAL OF ELECTROSTATICS
(2022)
Article
Chemistry, Multidisciplinary
Alisa R. Bogdanova, Dmitry V. Krasnikov, Eldar M. Khabushev, B. Javier A. A. Ramirez, Yakov E. Matyushkin, Albert G. Nasibulin
Summary: In this study, the effect of hydrogen on the growth of single-walled carbon nanotubes in the aerosol chemical vapor deposition process was investigated. It was shown that hydrogen inhibits the pyrolysis of ethylene, extending the synthesis parameter window. Three different regimes of hydrogen effect were distinguished: pyrolysis suppression at low concentrations, surface cleaning/activation promotion, and surface blockage/nanotube etching at high concentrations. This detailed study contributes to understanding the complex role of hydrogen and its impact on the synthesis of single-walled carbon nanotubes.
Article
Chemistry, Analytical
Masafumi Inaba, Takenori Oda, Masaki Kono, Nisarut Phansiri, Takahiro Morita, Shota Nakahara, Michihiko Nakano, Junya Suehiro
Summary: The study fabricated CNT/SnO2 heterojunction gas sensors using one-step dielectrophoretic assembly and investigated the effect of CNT/SnO2 ratio on gas detection properties. The results showed that the UV-irradiated CNT/SnO2 heterojunction gas sensor had a high response to 1 ppm NO2 in artificial air.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Review
Energy & Fuels
Jin-Myung Choi, Jiye Han, Tushar Rane, Soyeon Kim, Ick Soo Kim, Il Jeon
Summary: This review discusses the fundamentals of utilizing SWCNTs in PSCs, including their characteristics as electron-transporting layer, hole-transporting layer, photoactive layer, and interfacial materials. It also presents strategies to improve PSCs performance through defect control and enhancement of electrical and morphological properties.
JOURNAL OF PHYSICS-ENERGY
(2022)
Article
Nanoscience & Nanotechnology
Heather G. Wise, Hidemasa Takana, Anthony B. Dichiara
Summary: The continuous flow assembly of colloidal nanoparticles from aqueous suspensions into macroscopic materials using a field-assisted double flow focusing system allows the integration of renewable cellulose nanofibrils (CNFs) with single-walled carbon nanotubes (SWNTs) to produce high-performance functional filament nanocomposites. The nanoscale orientational anisotropy of the CNFs and SWNTs is achieved by an alternating electric field and extensional sheath flows. The resulting macroscopic filaments exhibit improved mechanical, electrical, and liquid sensing properties, showing promise for environmentally friendly and scalable manufacturing of multifunctional fibers.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Xueting Zhang, Liu Qian, Xiaojing Yao, Lili Zhang, Qianru Wu, Dong Li, Chen Ma, Nan Zhao, Liantao Xin, Chang Liu, Xiuyun Zhang, Jin Zhang, Maoshuai He
Summary: The past two decades have seen significant progress in the catalytic synthesis of single-walled carbon nanotubes (SWNTs) using non-conventional nanoparticles. This study presents the use of a solid magnesia (MgO) supported ruthenium (Ru) catalyst for chemical vapor deposition (CVD) growth of SWNTs. The results show successful synthesis of enriched (6, 5) SWNTs at high temperatures, partially attributed to the high activity of Ru clusters. The study also reveals the mechanism behind the activation of Ru clusters through charge transfer from the MgO support.
Article
Chemistry, Physical
Sunwoo Kim, Sehee Jung, Woo-Jae Kim
Summary: This study proposes an efficient method to produce vertically aligned multi-walled carbon nanotubes (VA-MWNT)-photocurable polymer hybrid materials, which can fortify the mechanical properties of polymer composites. The method involves arranging MWNTs in the vertical direction in polymer mixtures via electrophoresis and then curing the polymer through UV irradiation. The resulting composite showed significantly improved compressive force compared to the polymer itself and polymer with randomly dispersed MWNTs.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Nan Zhao, Qianru Wu, Xiuyun Zhang, Tao Yang, Dong Li, Xueting Zhang, Chen Ma, Runluan Liu, Liantao Xin, Maoshuai He
Summary: The synthesis of SWNTs from plastic polymers using chemical vapor deposition (CVD) relies on a robust Co-MgO cobalt catalyst. This method extends the potential of plastic waste as a feedstock for high-value carbon nanomaterials.
Article
Chemistry, Multidisciplinary
Qidong Liu, Feng Yang, Yan Zhang, Xue Zhao, Zeyao Zhang, Sheng Zhu, Yan Li
Summary: In this study, a new intermetallic compound catalyst, CoSi2, was developed for the selective growth of carbon nanotubes by chemical vapor deposition. The catalyst showed high selectivity for the synthesis of (11, 7) tubes and high purity of semiconducting SWCNTs. However, ethanol is not suitable as a carbon feedstock due to the sensitivity of CoSi2 to oxygen-containing environments at high temperatures.
Article
Chemistry, Multidisciplinary
Min-Ken Li, Adnan Riaz, Martina Wederhake, Karin Fink, Avishek Saha, Simone Dehm, Xiaowei He, Friedrich Schoeppler, Manfred M. Kappes, Han Htoon, Valentin N. Popov, Stephen K. Doom, Tobias Hertel, Frank Hennrich, Ralph Krupke
Summary: This work demonstrates that electroluminescence excitation is selective towards neutral defect-state configurations with the lowest transition energy, which, combined with gate control, leads to high spectral purity.
Article
Chemistry, Physical
Han Li, Christopher M. Sims, Rui Kang, Frank Biedermann, Jeffrey A. Fagan, Benjamin S. Flavel
Summary: In this study, highly purified (>80%) left- and right-handed (6,5) single-wall carbon nanotubes (SWCNTs) were separated using aqueous two-phase extraction (ATPE), with limited experimental steps. The optimized surfactant conditions were determined, and analytical ultracentrifugation (AUC) and near-infrared photoluminescence (PL) measurements were used to examine the required conditions for surfactant wrapping and partition coefficient change (PCCCs). This study provides valuable insights into the underlying mechanisms behind surfactant-assisted SWCNT separations and promotes the future use of SWCNT enantiomers in fundamental studies and applications.
Article
Chemistry, Physical
Qing Gao, Jun Yan, Han Li, Jingwei Chen, Xueliang Yang, Yuhua Bai, Xuning Zhang, Bingbing Chen, Jianxin Guo, Weiyuan Duan, Kaixin Han, Feng Li, Jianming Wang, Dengyuan Song, Shufang Wang, Benjamin S. Flavel, Jianhui Chen
Summary: This study demonstrates that commercially available SWCNT soots, combined with organic passivation technology, can serve as an efficient rear contact and alternative to ALD-Al2O3/PECVD-SiNx/laser treatment in conventional PERC solar cells, achieving a power conversion efficiency of over 23%. This approach is simple, scalable, and eliminates the issue of high interfacial recombination caused by metal-semiconductor contact in PERC technology.
Article
Chemistry, Multidisciplinary
Christian Rust, Pavel Shapturenka, Manuel Spari, Qihao Jin, Han Li, Andreas Bacher, Markus Guttmann, Ming Zheng, Tehseen Adel, Angela R. Hight Walker, Jeffrey A. Fagan, Benjamin S. Flavel
Summary: Dead-end filtration is an effective method for preparing aligned thin films of single-wall carbon nanotubes. This study focuses on the role of SWCNT length and diameter in the alignment process. Films were prepared from length-sorted fractions of small and large diameter SWCNTs, and the alignment was characterized using various microscopy and spectroscopy techniques. The findings suggest a law that relates the length of a carbon nanotube to its diameter and zeta potential.
Article
Chemistry, Multidisciplinary
Xin Zhou, Lu Wan, Han Li, Xueliang Yang, Jingwei Chen, Kunpeng Ge, Jun Yan, Cuili Zhang, Qing Gao, Xuning Zhang, Jianxin Guo, Feng Li, Jianming Wang, Dengyuan Song, Shufang Wang, Benjamin S. Flavel, Jianhui Chen
Summary: By using metal-assisted chemical etching (MACE) and a vacuum-free organic passivation layer, a low reflectance black silicon structure with long minority carrier lifetimes can be formed. This provides a feasible technical scheme for the multiple carrier generation through the inverse Auger effect.
Article
Chemistry, Multidisciplinary
Arijit Jana, Madhuri Jash, Wakeel Ahmed Dar, Jayoti Roy, Papri Chakraborty, Ganesan Paramasivam, Sergei Lebedkin, Kaplan Kirakci, Sujan Manna, Sudhadevi Antharjanam, Jan Machacek, Monika Kucerakova, Sundargopal Ghosh, Kamil Lang, Manfred M. Kappes, Tomas Base, Thalappil Pradeep
Summary: This study presents a new class of thermally stable tetranuclear copper nanoclusters (Cu-4@oCBT, Cu-4@mCBT and Cu-4@ICBT) with tunable solid-state luminescence. They exhibit bright phosphorescence in their crystalline forms. Cu-4@oCBT and Cu-4@mCBT are green emitting, while Cu-4@ICBT is orange emitting. DFT calculations reveal the nature of their electronic transitions. Cu-4@oCBT and Cu-4@mCBT are thermally stable up to 400 degrees C, while Cu-4@ICBT is structurally flattened.
Article
Chemistry, Multidisciplinary
Papri Chakraborty, Sami Malola, Marco Neumaier, Patrick Weis, Hannu Hakkinen, Manfred M. Kappes
Summary: The fragmentation dynamics of ligated coinage metal clusters provides insights into their structural and bonding properties. However, the challenges in methodology have limited the investigation of fragment structures. In this study, we used trapped ion mobility mass spectrometry to determine the geometric structures of the primary fragments of [Ag29L12](3-) and compared them to density functional theory calculations. We also observed a new dissociation channel in the further dissociation of [Ag19L6](-), indicating a competition between retaining electronic stability and increasing steric strain of ligands and staples. These findings have potential implications for studying the catalytic behavior of Ag clusters on supports through soft-landing deposition.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Vanitha R. Naina, Akhil K. Singh, Pascal Rauthe, Sergei Lebedkin, Michael T. Gamer, Manfred M. Kappes, Andreas-Neil Unterreiner, Peter W. Roesky
Summary: In this study, a coumarin functionalized aminodiphosphine was used as a bidentate ligand to synthesize mono-, di-, and trimetallic copper and silver complexes. The ligand exhibited rich luminescence properties, including blue fluorescence and green phosphorescence. Red phosphorescence was observed in the trinuclear complexes at low temperatures. The excited states in these compounds were investigated using femtosecond transient absorption spectroscopy and quantum chemical calculations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemical Research Methods
Papri Chakraborty, Marco Neumaier, Patrick Weis, Manfred M. Kappes
Summary: Cyclodextrin (CD) macrocycles are used to create various supramolecular architectures for applications including gas adsorption, drug delivery, and catalysis. However, predicting their assemblies and identifying possible isomers in CD oligomers has been challenging due to their dynamic nature. In this study, CD oligomers linked by Cu2+ metal ions were created and characterized using mass spectrometry and trapped ion mobility spectrometry, allowing the separation and estimation of isomers. The isomeric heterogeneity reflects the size-specific packing patterns of individual CDs, and the existence of kinetically trapped structures was also observed.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Chemistry, Physical
Sreekanta Debnath, Alexander Schaefer, Karolina A. Haupa, Dmitry Strelnikov, Jana Roithova, Juraj Jasik, Sergei Lebedkin, Manfred M. Kappes
Summary: Helium tagging photodissociation action spectroscopy and laser-induced fluorescence spectroscopy in neon matrix were used to study the photophysics of electrosprayed rhodamine B cation at low temperatures. The experiments were conducted using He-TAG apparatus for helium tagging and Depo-II machine for LIF measurements. The resulting electronic spectra provide benchmarks for theoretical description of this organic dye.
Article
Materials Science, Multidisciplinary
Nicolas Frederic Zorn, Simon Settele, Shen Zhao, Sebastian Lindenthal, Abdurrahman Ali El Yumin, Tim Wedl, Han Li, Benjamin Scott Flavel, Alexander Hoegele, Jana Zaumseil
Summary: Semiconducting single-walled carbon nanotubes (SWCNTs) have outstanding electrical and optical properties, making them highly suitable for optoelectronic devices. However, the luminescence spectra of SWCNT thin films on commonly used substrates are often compromised by broadening of the main excitonic emission and unwanted low-energy sidebands. Surface passivation with a low dielectric constant polymer enhances the emission properties of SWCNTs and enables the fabrication of high-performance light-emitting field-effect transistors. Passivation with this polymer is proposed as a standard treatment for substrates used in spectroscopic investigations and optoelectronic devices with SWCNTs and other low-dimensional emitters.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Verena Hoehn, Wolfram Feuerstein, Florian R. Rehak, Max Kehry, Sergei Lebedkin, Manfred M. Kappes, Wim Klopper, Frank Breher
Summary: The synthesis of C-C-P pre-ligands based on a dicyclohexylphosphine-substituted biphenyl framework has been reported. The pre-ligands can form non-palindromic pincer complexes of Pt-II and PdII through double oxidative addition and subsequent comproportionation or C-H activation. These complexes exhibit similar green phosphorescence in both the solid state and solution, with a more pronounced vibronic pattern observed in the solid samples at cryogenic temperatures.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Christoph Schissler, Erik K. Schneider, Michael Rotter, Silke Notter, Carsten Geier, Patrick Weis, Manfred M. Kappes, Stefan Braese
Summary: We have developed a synthetic route to achieve cofacial stacking of N-fused porphyrins and regular porphyrins using an o-substituted phenylene linker. This approach involves a crucial Suzuki-Miyaura cross-coupling reaction to introduce a phenyl moiety into the tri-pentacyclic ring of the N-fused porphyrin, enabling the formation of a spatial arrangement that can hold both N-fused porphyrin and regular porphyrin in close proximity. The resulting ligand system was obtained with a 0.77% yield in five steps and was characterized using various techniques.
Article
Chemistry, Physical
Yuhua Bai, Qing Gao, Bingbing Chen, Wenheng Li, Xuning Zhang, Dehua Yang, Xueliang Yang, Jun Yan, Jingwei Chen, Jianming Wang, Dengyuan Song, Shufang Wang, Han Li, Benjamin S. Flavel, Jianhui Chen
Summary: Carbon/silicon heterojunctions have a great potential for silicon solar cells. Carbon nanotubes (CNTs) have achieved high power conversion efficiency and small device size in particular with organic passivation and a back-junction design. However, the interdigitated back contact (IBC) cell, the current state-of-the-art device geometry for silicon photovoltaics, has not been demonstrated for CNT/Si solar cells due to fabrication complexity. This study demonstrates IBC-CNT solar cells with high efficiency and large area using a simple spin coating process and evaporation of buried silicon oxide/magnesium electron-selective contacts.
Article
Chemistry, Physical
Sreekanta Debnath, Alexander Schaefer, Shun Ito, Dmitry Strelnikov, Rabea Schneider, Karolina A. Haupa, Manfred M. Kappes
Summary: By comparing the photophysical properties of a cation and its neutral radical, it was found that the cation exhibited efficient visible photoluminescence while the neutral species showed no emission. Additionally, electronic preresonance Raman spectra were observed for the cation, indicating a significant efficiency factor. These characteristics of the cation/neutral pair may have implications in the field of in vivo bioimaging microscopy and stimulated Raman spectroscopy.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
