Article
Materials Science, Ceramics
Shiming Hao, Pengru Liu, Haozhan Wu, Huifang Wang, Jingpei Xie
Summary: SiC nanopowders were synthesized using silicon powders and expanded graphite as initial materials, and ferric nitrate as catalyst precursor. The effects of heat treatment temperature and the C/Si molar ratio on SiC products were investigated. The microstructure, phase composition, chemical state, and photoluminescence properties of the products were analyzed. The results showed that the 3C-SiC product had a higher content when heat-treated at 1400 degrees C for 3 hours with a C/Si molar ratio of 1:1. The formation process of 3C-SiC could be explained by a two-step method, and it exhibited potential applications in ultraviolet detectors, optoelectronic devices, and light emitters.
CERAMICS INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
Meng Yuan, Mingkun Zhang, Zhao Fu, Shan Han, Yuning Zhang, Shaoxiong Wu, Rongdun Hong, Xiaping Chen, Jiafa Cai, Dingqu Lin, Zhengyun Wu, Baoping Zhang, Jicheng Wang, Feng Zhang
Summary: A significant enhancement in ultraviolet (UV) detection is achieved by etching microhole arrays and utilizing localized surface plasmon resonance (LSPR) of aluminum nanoparticles (NPs) on 4H-SiC metal-semiconductor-metal (MSM) photodetectors (PDs). The PDs with different microhole diameters demonstrate an ultralow dark current at a bias of 5V. The PD with 3μm microholes shows the best performance with a responsivity 35% higher than the device without microholes. The combination of 3μm microholes and aluminum NPs results in a nearly 6 times enhancement in peak responsivity compared to the device without aluminum NPs.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Xiao Guo, Zeyu Peng, Pengbo Ding, Long Li, Xinyi Chen, Haoyun Wei, Zhen Tong, Liang Guo
Summary: Silicon carbide (SiC), as a leading representative of the third-generation of semiconductors, has excellent physical properties but poses challenges in processing, requiring special techniques such as femtosecond laser machining. SiC shows unprecedented potential for optoelectronic applications, necessitating measurement of its nonlinear optical properties and exploration of its potential applications.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Materials Science, Multidisciplinary
Victor A. Soltamov, Boris Yavkin, Andrey N. Anisimov, Harpreet Singh, Anna P. Bundakova, Georgy Mamin, Sergei B. Orlinskii, Evgeniy N. Mokhov, Dieter Suter, Pavel G. Baranov
Summary: The study demonstrates coherent spin manipulations of spin-3/2 color center ensembles in 6H-SiC crystal under high magnetic fields, showing room temperature control and a decrease in relaxation times T-1 and T-2 with increasing temperature and magnetic field strength. The experiments also reveal the potential for optically detecting the spin alignment between M-S = +/- 3/2 in spin-3/2 color centers through optically pumped silent M-S = +/- 1/2 sublevels, including the observation of Rabi oscillations.
Article
Engineering, Mechanical
Zhonghuai Wu, Liangchi Zhang, Shengyao Yang, Chuhan Wu, Kemi Xu, Dezhi Zheng
Summary: Using large-scale molecular dynamics simulations, this study investigated the influence of processing temperature on the deformation of single crystal 6H-SiC during nanoscratching comprehensively. The study covered a wide range of temperature variations, from 1 K to 900 K. It was observed that as the processing temperature increased, the material removal mechanism of 6H-SiC transitioned from intermittent cleavage to continuous plastic deformation. The deformation mechanism involved surface amorphization and subsurface dislocations mainly in the cubic diamond structural layer. The processing temperature had a significant impact on dislocation distribution, groove morphology, scratching forces, and coefficient of friction. The anisotropic effect on chip formation decreased with increasing processing temperature. Evaluation of surface roughness and maximum subsurface damage depth concluded that the scratched surface/subsurface quality of 6H-SiC deteriorated with increasing processing temperature.
Article
Materials Science, Multidisciplinary
Z. Cheng, W. Lu, J. Shi, D. Tanaka, N. H. Protik, S. Wang, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, H. Amano, S. Graham
Summary: This study investigated the temperature-dependent thermal conductivity of doped epitaxial 6H-SiC and monocrystalline porous 6H-SiC below room temperature using time-domain thermoreflectance, revealing strong quasi-ballistic thermal transport. Doping and structural boundaries were applied to tune the quasi-ballistic thermal transport, with observations on the selective scattering effects of nitrogen and boron dopants on phonon transport.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
K. Kamalakkannan, R. Rajaraman, B. Sundaravel, G. Amarendra, K. Sivaji
Summary: Depth-resolved Raman spectroscopy was used to study the changes in sem-insulating 6H-Silicon Carbide (SI:6H-SiC) after Al+ ion implantation and annealing at 800 degrees C. Results showed deformations related to bond breakages and defect recovery, which were observed through the analysis of Raman first-order acoustical and second-order optical phonon modes. Annealing led to symmetrical Raman peaks and the recovery of active Raman modes. The Raman Z-scan studies revealed amorphous features near the surface and partial recovery in the deep region, indicating defect agglomeration and recrystallization.
Article
Materials Science, Multidisciplinary
Jiawen Zhou, Cheng Wang, Ming Song, Xianhui Chen, Weidong Xia
Summary: An atmospheric non-thermal arc plasma source based on magnetically stabilized gliding arc discharge was developed for the continuous preparation of ultrafine amorphous silicon carbide (a-SiC) nanoparticles via hexamethyldisilane decomposition. The synthesized nanoparticles showed strong blue-green light emission and had abundant functional groups and oxidized overlayers on their surface. Low input energy favored the synthesis of a-SiC nanoparticles, while high input energy promoted the transition from amorphous structure to b-SiC.
Article
Chemistry, Physical
Yuanyuan Li, Xiaoyu Liu, Tianyuan Liang, Wenjie Liu, Jiyang Fan
Summary: The study shows that SiC quantum dots with small dimensions can naturally oxidize at a lower temperature to form core/shell and heteroepitaxial SiC/SiO2 quantum dots. The surface silica layer enhances the quantum efficiency by improving the carrier potential barrier and reducing the nonradiative transition rate, making it suitable for nanoscale electronic and photonic devices.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Applied
Kouichi Hayashi, Maximilian Lederer, Yohei Fukumoto, Masashi Goto, Yuta Yamamoto, Naohisa Happo, Masahide Harada, Yasuhiro Inamura, Kenichi Oikawa, Kenji Ohoyama, Peter Wellmann
Summary: The local structure around boron doped in 6H-type silicon carbide was investigated using neutron holography. Reconstructed three-dimensional atomic images showed that boron substituted for both silicon and carbon, primarily located at the Si-C-cubic site layer. Boundaries above the boron locations were suggested from the absence of atomic images in the upper region of reconstruction.
APPLIED PHYSICS LETTERS
(2022)
Article
Quantum Science & Technology
I. D. Breev, Z. Shang, A. Poshakinskiy, H. Singh, Y. Berencen, M. Hollenbach, S. S. Nagalyuk, E. N. Mokhov, R. A. Babunts, P. G. Baranov, D. Suter, S. A. Tarasenko, G. Astakhov, A. N. Anisimov
Summary: Controllable solid-state spin qubits are important for applied quantum technologies. This study investigates the optical and spin properties of atomic-scale qubits in SiC, and reveals the inverted excited-state fine structure of a specific silicon-vacancy in the 6H-SiC polytype. The study also explores the impact of competing optical spin pumping mechanisms on the spin readout contrast.
NPJ QUANTUM INFORMATION
(2022)
Article
Engineering, Mechanical
Zhonghuai Wu, Liangchi Zhang, Weidong Liu
Summary: This paper comprehensively studied the structural anisotropy effect on the nanoscratching of 6H-SiC using large-scale molecular dynamics simulations. Different combinations of scratching conditions resulted in significant variations in scratching-induced deformation morphology, activated dislocations, and scratching forces due to the strong anisotropy effect of the material. The basal plane (0001) along < 1100 > direction was identified as the best combination for conducting nanoscratching on 6H-SiC.
Article
Materials Science, Multidisciplinary
Harpreet Singh, Andrey N. Anisimov, Pavel G. Baranov, Dieter Suter
Summary: This research focuses on the study of charged silicon vacancies in silicon carbide (SiC), specifically in the 6H-SiC polytype. Optically detected magnetic resonance (ODMR) spectra were used to correlate optical and magnetic resonance signals and separate signals from different vacancies. The results also explained the observed temperature-dependent changes in the ODMR signal.
MATERIALS RESEARCH EXPRESS
(2023)
Article
Engineering, Mechanical
Zhonghuai Wu, Liangchi Zhang, Shengyao Yang
Summary: This paper investigates the effects of nanogrinding-induced defects on the deformation of 6H-SiC using molecular dynamic analyses. The study found that nanogrinding inevitably results in a damage layer containing amorphous phase transformation and discrete dislocations. This damage significantly affects subsequent deformation, surface morphology, grinding force, and coefficient of friction. The deformation mechanism of 6H-SiC transitions from plastic flow within the amorphous layer to the propagation of existing dislocations and finally to the nucleation of new dislocations under the interactions with consecutive abrasives. The remnant amorphous layer on the ground surface can be minimized if the grinding depth of subsequent grains is less than the thickness of the first amorphous layer.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Materials Science, Ceramics
Xin Wang, Tao Yang, Xinmei Hou, Yapeng Zheng, Enhui Wang, Zhengtao Du, Sheng Cao, Hailong Wang
Summary: Silicon carbide nanowires (SiC NWs) were synthesized using graphene and Si powder, forming a 2H/3C-SiC heterojunction structure, with significant blue shift in the photoluminescence spectra due to structural defects.
CERAMICS INTERNATIONAL
(2022)
Article
Mycology
Luisa Mandrile, Antonietta Mello, Alfredo Vizzini, Raffaella Balestrini, Andrea Mario Rossi
MYCOLOGICAL PROGRESS
(2020)
Article
Optics
Hamidreza Chalabi, Sabyasachi Barik, Sunil Mittal, Thomas E. Murphy, Mohammad Hafezi, Edo Waks
Article
Optics
Sarvenaz Memarzadeh, Jongbum Kim, Yigit Aytac, Thomas E. Murphy, Jeremy N. Munday
Article
Optics
Kunyi Zhang, Andrew P. Lawson, Chase T. Ellis, Matthew S. Davis, Thomas E. Murphy, Hans A. Bechtel, Joseph G. Tischler, Oded Rabin
Article
Optics
Ramesh Kudalippalliyalil, Thomas E. Murphy, Karen E. Grutter
Review
Materials Science, Multidisciplinary
Martin Mittendorff, Stephan Winnerl, Thomas E. Murphy
Summary: This article explores the potential of 2D materials for THz applications, summarizes recent research in the field, and outlines the challenges and opportunities that lie ahead in this promising new area.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Optics
Sai Kanth Dacha, Thomas E. Murphy
Article
Chemistry, Multidisciplinary
In Young Kim, Tae Geol Lee, Vytas Reipa, Min Beom Heo
Summary: TiO2 NPs induce caspase-dependent apoptosis, reactive oxygen species generation, and lysosomal membrane permeabilization in HaCaT cells under UVA irradiation, suggesting that LMP-dependent oxidative stress plays a critical role in the UVA phototoxicity of TiO2 NPs in HaCaT cells. The cytotoxicity of TiO2 NPs is not significant without UVA irradiation.
Article
Optics
Sai Kanth Dacha, Wenqi Zhu, Amit Agrawal, Kenneth J. Ritter, Thomas E. Murphy
Summary: We experimentally demonstrate a unique power-dependent rotation effect in the vectorial mode superposition of two spin-orbit coupled orbital angular momentum (OAM) modes, which co-propagate in the Kerr nonlinear regime in a hollow ring-core optical fiber. The added spatial dimension produces a visually observable rotation of the spatial pattern emerging from the fiber when imaged through a linear polarizer.
Article
Optics
Nicole Menkart, Joseph D. Hart, Thomas E. Murphy, Rajarshi Roy
Summary: This study focuses on characterizing the statistical properties of dark counts in single-photon detectors, particularly SPADs made for 1550 nm. Results show that the measured distributions often differ significantly from Poisson due to the presence of dead time and afterpulsing, highlighting the need for corrections. By applying an iterative algorithm, the dead time effects were successfully removed from the probability distribution to obtain Poisson distributions, providing a systematic procedure for obtaining accurate photocount statistics.
Article
Optics
Evan Dowling, Mark Morris, Gerald Baumgartner, Rajarshi Roy, Thomas E. Murphy
Summary: Quantum measurements using entangled photons' polarization require calibration and alignment of the bases between observers. The changing birefringence in optical fibers makes the polarization state unpredictable, posing challenges to classical methods. A fast automatic alignment method using the Nelder-Mead simplex method is introduced, demonstrating successful alignment in both deployed and controlled scenarios.
Article
Engineering, Electrical & Electronic
Charles J. Turner, Thomas Stevenson, Robin Cantor, Lawrence Hilliard, Thomas E. Murphy, Berhanu Bulcha
Summary: This article presents a high-rejection, thin-film high-temperature superconductor, microstrip bandstop filter to prevent interference from a local and high-power radio-frequency source. The filter has excellent characteristics such as a wide bandwidth and reduced fringing electric fields. The YBCO films were accurately modeled and tested at 77 K.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Charles J. Turner, Andrew I. Harris, Thomas E. Murphy, Mark Stephen
Summary: Microwave photonic circuits can process large bandwidths of radiometric data in numerous analog spectrometer channels with narrow spectral resolutions and a small device footprint. However, the processing of the entire bandwidth simultaneously requires a large dynamic range. In this study, a heterodyne photonic radiometer is assembled and tested with a microwave thermal noise source. The results demonstrate the 1 dB output power compression point for a thermal noise signal occurs at approximately half of the average input power compared to a continuous wave signal. These findings have significant implications for future photonic radiometer designs.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Optics
Matthew L. Chin, Sebastian Matschy, Florian Stawitzki, Jayaprakash Poojali, Hassan A. Hafez, Dmitry Turchinovich, Stephan Winnerl, Gagan Kumar, Rachael L. Myers-Ward, Matthew T. Dejarld, Kevin M. Daniels, H. Dennis Drew, Thomas E. Murphy, Martin Mittendorff
Summary: Graphene patterned into plasmonic structures like ribbons or discs can greatly enhance optical interactions, with the nonlinear optical response controlled by hot carriers. In magnetic fields, the plasmon hybridizes with cyclotron resonance, leading to a splitting of plasmonic absorption. This splitting can be used to tune the nonlinear optical response of graphene discs.
JOURNAL OF PHYSICS-PHOTONICS
(2021)
Article
Materials Science, Multidisciplinary
M. Mehdi Jadidi, Mehdi Kargarian, Martin Mittendorff, Yigit Aytac, Bing Shen, Jacob C. Koenig-Otto, Stephan Winnerl, Ni Ni, Alexander L. Gaeta, Thomas E. Murphy, H. Dennis Drew
