Article
Chemistry, Physical
Cong Su, Fang Zhang, Salman Kahn, Brian Shevitski, Jingwei Jiang, Chunhui Dai, Alex Ungar, Ji-Hoon Park, Kenji Watanabe, Takashi Taniguchi, Jing Kong, Zikang Tang, Wenqing Zhang, Feng Wang, Michael Crommie, Steven G. Louie, Shaul Aloni, Alex Zettl
Summary: Colour centre emission from hexagonal boron nitride (hBN) shows promise for quantum technologies, but activation and tuning are challenging. In this study, the authors demonstrate the tuning of emission brightness by adjusting the twist angle and modulation of brightness with external voltage at the twisted interface of hBN flakes.
Article
Multidisciplinary Sciences
Toshiyuki Tashima, Hideaki Takashima, Andreas W. Schell, Toan Trong Tran, Igor Aharonovich, Shigeki Takeuchi
Summary: In this study, a hybrid system of a nanofibre Bragg cavity (NFBC) and ensemble defect centres in hBN nanoflakes is realized. By fabricating the NFBC using a helium-focused ion beam (FIB) system and developing a manipulation system to place hBN nanoflakes onto the cavity region, a sharp emission peak is observed at the resonant wavelength of the NFBC.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
Yutong He, Thomas G. Blackburn, Toma Toncian, Alexey V. Arefiev
Summary: The study demonstrates the possibility of generating electrons and positrons from light alone using high-intensity two-beam laser facilities and advanced target designs. The simulations show that high-density gamma rays can create a large number of positrons, which can be accelerated to energies exceeding 200 MeV. This research opens up new possibilities for positron generation and acceleration in experimental settings.
COMMUNICATIONS PHYSICS
(2021)
Article
Physics, Multidisciplinary
Marco Capelli, Lukas Lindner, Tingpeng Luo, Jan Jeske, Hiroshi Abe, Shinobu Onoda, Takeshi Ohshima, Brett Johnson, David A. Simpson, Alastair Stacey, Philipp Reineck, Brant C. Gibson, Andrew D. Greentree
Summary: The nitrogen-vacancy colour centre in diamond is an important solid-state quantum system with various applications. This study reveals that nearby nitrogen impurities can quench the emission of nitrogen-vacancy centres, resulting in a reduced fluorescence quantum yield. The researchers also measured the emission properties of these centres in synthetic diamond samples with different concentrations of nitrogen impurities. The results show that increasing nitrogen density leads to a decrease in lifetime and fluorescence quantum yield of nitrogen-vacancy centres.
NEW JOURNAL OF PHYSICS
(2022)
Article
Quantum Science & Technology
Lukas Hunold, Stefano Lagomarsino, Assegid M. Flatae, Haritha Kambalathmana, Florian Sledz, Silvio Sciortino, Nicla Gelli, Lorenzo Giuntini, Mario Agio
Summary: This research presents the scalable production of silicon-vacancy color centers in single-crystal diamond by ion implantation for the fabrication of quantum emitters. The lateral position of SiV is spatially controlled using a 1-micrometer pinhole, while the initial implantation position is monitored by ion beam position and scattering through the pinhole. This study also discusses the role of ions scattered by the pinhole and the activation yield of SiV color centers for the creation of single quantum emitters.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Review
Geosciences, Multidisciplinary
Francesca Giuliani, Anna De Falco, Valerio Cutini
Summary: This paper critically reviews the challenges that Italy faces in reducing seismic risk and protecting historic centers, emphasizing the importance of historic monuments in earthquake risk management. It suggests further research on developing a comprehensive disaster risk reduction framework for resilience-enhancing challenges in historic centers in Italy.
INTERNATIONAL JOURNAL OF DISASTER RISK REDUCTION
(2021)
Article
Materials Science, Multidisciplinary
Hideaki Takashima, Atsushi Fukuda, Konosuke Shimazaki, Yusuke Iwabata, Hiroki Kawaguchi, Andreas W. Schell, Toshiyuki Tashima, Hiroshi Abe, Shinobu Onoda, Takeshi Ohshima, Shigeki Takeuchi
Summary: Research on creating nanodiamonds with SiV centers via Si ion implantation found that high-temperature annealing treatment can reduce the ZPL linewidth, making it close to that of nanodiamonds synthesized by CVD.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Engineering, Electrical & Electronic
Kee Suk Hong, Hee-Jin Lim, Dong Hoon Lee, In-Ho Bae, Kwang-Yong Jeong, Christoph Becher, Sejeong Kim, Igor Aharonovich
Summary: Single-photon sources based on single emitters are highly interesting for various applications and have been realized using different materials. Common factors related to relaxation times of internal states indirectly affect the photon number stability. GaN emitters demonstrate higher stability due to faster relaxation times compared to hBN emitters, but hBN emitters have higher photon generation rates. Repeatable radiant flux measurements of a bright hBN single-photon emitter for a wide range of fluxes have been demonstrated.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Review
Physics, Multidisciplinary
S. Lagomarsino, A. M. Flatae, H. Kambalathmana, F. Sledz, L. Hunold, N. Soltani, P. Reuschel, S. Sciortino, N. Gelli, M. Massi, C. Czelusniak, L. Giuntini, M. Agio
Summary: Silicon-vacancy (SiV) centers in diamond are being increasingly studied for their potential applications in quantum communication and sensing. Different fabrication methods can influence the optical properties of SiV centers, while polycrystalline micro and nanostructures are of interest for nano-optics applications.
FRONTIERS IN PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
V. Mortet, A. Taylor, M. Davydova, M. Lamac, N. Lambert, I. Elantyev, J. Lorincik, D. Troadec, M. Vronka, S. Potocky
Summary: This study investigates the effect of pulsing methane during microwave plasma enhanced chemical vapor deposition on the growth of phosphorus-doped diamond, aiming to increase the doping efficiency and maximum concentration.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Optics
Xin Wang, Pengfei Zhang, Gang Li, Tiancai Zhang
Summary: A scheme is proposed to enhance the coupling efficiency of photons from a single quantum emitter into a hole-tailored nanofiber, achieving a coupling efficiency of 62.8% and broad application prospects.
Article
Chemistry, Physical
Oliver Lerstol Hebnes, Marianne Etzelmueller Bathen, Oyvind Sigmundson Schoyen, Sebastian G. Winther-Larsen, Lasse Vines, Morten Hjorth-Jensen
Summary: This research develops a framework for the automated discovery of semiconductor platforms for quantum technologies using material informatics and machine learning methods. By considering findings from the literature and different features, it is found that features related to crystal structure and symmetry play an important role in predicting materials suitable for quantum technologies.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Business
Rahul Sindhwani, Punj Lata Singh, Abhishek Behl, Mohd. Shayan Afridi, Debaroti Sammanit, Aviral Kumar Tiwari
Summary: This study aims to identify the key hindering factors for different firms' progress in net-zero emission technologies and methods, highlighting the importance of focusing on issues in management and professional expertise.
TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE
(2022)
Article
Physics, Applied
A. A. Emelyanov, V. A. Pinaev, M. Yu Plotnikov, A. K. Rebrov, N. Timoshenko, I. B. Yudin
Summary: The paper describes the synthesis of diamonds using the gas-jet deposition method with microwave activation of precursor gases. The optimal methane concentration for this method is found to be around 1% within the given range of parameters.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Monalisa Garai, Ziyu Zhu, Jia Shi, Shisheng Li, Qing-Hua Xu
Summary: In this study, the plasmon modulated emission of MoS2 in various plasmon-MoS2 hybrid structures was investigated at the single-particle level. Gold (Au) nanoantennas of different shapes were used to explore the particle shape effects, with Au nanotriangles showing the highest enhancement factor and Au nanospheres showing the lowest. Numerical simulation results indicated that the enhancement primarily stemmed from an increased quantum yield, with excitation efficiency playing a minor role. The quantum yield enhancement was influenced by both the sharp tips and contact mode of the Au nanoantenna with MoS2. Additionally, the polarization of MoS2 emission was modulated by the plasmon mode of the Au nanoantenna.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Lukas Mai, Felix Mitschker, Claudia Bock, Alessia Niesen, Engin Ciftyurek, Detlef Rogalla, Johannes Mickler, Matthias Erig, Zheshen Li, Peter Awakowicz, Klaus Schierbaum, Anjana Devi
Article
Chemistry, Inorganic & Nuclear
Dennis Zywitzki, Dereje H. Taffa, Laura Lamkowski, Manuela Winter, Detlef Rogalla, Michael Wark, Anjana Devi
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Physical
David Zanders, Ji Liu, Jorit Obenlueneschloss, Claudia Bock, Detlef Rogalla, Lukas Mai, Michael Nolan, Sean T. Barry, Anjana Devi
Summary: This work introduces a new approach for the atomic layer deposition (ALD) of metallic Co thin films, utilizing a thermal ALD process with CoCl2(TMEDA) precursor and Zn aminoalkyl compound as reducing agent. The research investigates the precursors' saturation behavior, film growth characteristics, and proposes reaction steps leading to pure Co film formation, confirmed by density functional theory (DFT) calculations. Thorough analysis of the Co thin films obtained from the process reveals the coexistence of carbon species in the film bulk, with promising resistivity values without postgrowth treatment.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Physical
Sebastian M. J. Beer, Arbresha Muriqi, Patrick Lindner, Manuela Winter, Detlef Rogalla, Michael Nolan, Andreas Ney, Jorg Debus, Anjana Devi
Summary: Europium sulfide (EuS) thin films grown via chemical vapor deposition (CVD) exhibit high quality, stoichiometry, and tunability, with the advantage of avoiding the use of toxic hydrogen sulfide.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Nils Boysen, Anish Philip, Detlef Rogalla, Maarit Karppinen, Anjana Devi
Summary: Cu and Ag precursors that are volatile, reactive, and thermally stable are currently of high interest for their application in atomic-layer deposition (ALD) of thin metal films. In pursuit of new precursors for coinage metals, namely Cu and Ag, a series of new N-heterocyclic carbene (NHC)-based Cu-I and Ag-I complexes were synthesized. Modifications in the substitution pattern of diketonate-based anionic backbones led to five monomeric Cu complexes and four closely related Ag complexes with the general formula [M((NHC)-N-tBu)(R)] (M=Cu, Ag; (NHC)-N-tBu=1,3-di-tert-butyl-imidazolin-2-ylidene; R=diketonate). Thermal analysis indicated that most of the Cu complexes are thermally stable and volatile compared to the more fragile Ag analogs. One of the promising Cu precursors was evaluated for the ALD of nanoparticulate Cu metal deposits by using hydroquinone as the reducing agent at appreciably low deposition temperatures (145-160 degrees C). This study highlights the considerable impact of the employed ligand sphere on the structural and thermal properties of metal complexes that are relevant for vapor-phase processing of thin films.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Dennis Zywitzki, Raoul Schaper, Engin Ciftyuerek, Jan-Lucas Wree, Dereje H. Taffa, Daniel M. Baier, Detlef Rogalla, Yujiao Li, Michael Meischein, Alfred Ludwig, Zheshen Li, Klaus Schierbaum, Michael Wark, Anjana Devi
Summary: Transition metal ferrites (such as CFO and NFO) have gained attention as potential materials for supercapacitors, with CVD processes offering advantages in producing high-quality, uniform, and dense ferrite films. Electrodes deposited on conducting substrates exhibit pseudocapacitive behavior, with high interfacial capacitances.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Tobias Horst Piotrowiak, Rico Zehl, Ellen Suhr, Lars Banko, Benedikt Kohnen, Detlef Rogalla, Alfred Ludwig
Summary: The formation of single-phase regions during the fabrication of La-Co-based oxide films is observed. Due to the high reactivity of La and the low formation energies of La2O3 and La-perovskites, the reactive sputter deposition process partially resembles the chemical vapor deposition process.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
David Zanders, Jorit Obenlueneschloss, Jan-Lucas Wree, Julia Jagosz, Parmish Kaur, Nils Boysen, Detlef Rogalla, Aleksander Kostka, Claudia Bock, Denis Oehl, Michael Gock, Wolfgang Schuhmann, Anjana Devi
Summary: Two novel ruthenium complexes belonging to the Ru(II)(DAD)(Cym) compound family are introduced as promising precursors. The chemical nature, potential for CVD and ALD, as well as the nonoxidative CVD processes for high-quality Ru thin films are demonstrated. The catalysis evaluation of the films in the OER shows promising performances.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Tim Hasselmann, Bujamin Misimi, Nils Boysen, David Zanders, Jan-Lucas Wree, Detlef Rogalla, Tobias Haeger, Florian Zimmermann, Kai Oliver Brinkmann, Sebastian Schaedler, Detlef Theirich, Ralf Heiderhoff, Anjana Devi, Thomas Riedl
Summary: In this study, highly conductive silver films were successfully grown at low temperatures using plasma-enhanced spatial ALD with a newly introduced nitrogen-based silver precursor. These silver films, used as bottom electrodes in organic solar cells, showed comparable performance to those made by traditional high-temperature vacuum processes.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Inorganic & Nuclear
Niklas Huster, Ramin Ghiyasi, David Zanders, Detlef Rogalla, Maarit Karppinen, Anjana Devi
Summary: Tin monoxide (SnO) films were successfully prepared using atomic layer deposition (ALD) technique. A suitable precursor was chosen for the growth of SnO films at low temperatures. The structure and optical properties of the films were characterized using various analytical tools.
DALTON TRANSACTIONS
(2022)
Article
Engineering, Electrical & Electronic
Jan-Lucas Wree, Jean-Pierre Glauber, David Zanders, Detlef Rogalla, Malte Becher, Matthew B. E. Griffiths, Andreas Ostendorf, Sean T. Barry, Andreas Ney, Anjana Devi
Summary: Researchers have successfully grown high-quality ferromagnetic CoS2 thin films using a tailored metalorganic chemical vapor deposition method, and have studied their magnetic properties. These findings could provide a foundation for the large-area application of CoS2 in different technological fields.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Inorganic & Nuclear
Sebastian M. J. Beer, Nils Boysen, Arbresha Muriqi, David Zanders, Thomas Berning, Detlef Rogalla, Claudia Bock, Michael Nolan, Anjana Devi
Summary: A series of closely related Y(III) compounds with formamidinate ligands were synthesized and characterized for potential use as precursors for yttrium oxide thin films via ALD. The compound with enhanced thermal stability was selected for ALD process development, resulting in high quality Y2O3 films with promising dielectric properties in MIS capacitor structures, confirmed by experimental and theoretical studies.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Xiao Wang, Detlef Rogalla, Aleksander Kostka, Alfred Ludwig
Summary: A thin-film materials library was fabricated in the V-Bi-O system using reactive co-sputtering. It was found that the solubility limit of Bi in VO2 is approximately 0.29 at%, and the phase transformation temperatures of VO2:Bi as well as the V5+/V4+ ratio are significantly affected by the Bi content.
Article
Chemistry, Multidisciplinary
Nils Boysen, David Zanders, Thomas Berning, Sebastian M. J. Beer, Detlef Rogalla, Claudia Bock, Anjana Devi
Summary: The use of the new precursor Y(DPfAMD)(3) in water-assisted thermal atomic layer deposition (ALD) process allows for the fabrication of high quality Y2O3 thin films with improved stability and characteristics. These films exhibit smooth, homogeneous, and polycrystalline properties, with excellent electrical performance suitable for gate oxides in semiconductor devices.
Article
Chemistry, Multidisciplinary
Nils Boysen, Bujamin Misimi, Arbresha Muriqi, Jan-Lucas Wree, Tim Hasselmann, Detlef Rogalla, Tobias Haeger, Detlef Theirich, Michael Nolan, Thomas Riedl, Anjana Devi
CHEMICAL COMMUNICATIONS
(2020)