Article
Optics
Yue Zhou, Dawei Bi, Songlin Wang, Longsheng Wu, Yi Huang, Enxia Zhang, Daniel M. Fleetwood, Aimin Wu
Summary: In this study, the radiation responses of silicon photonic passive devices in silicon-on-insulator technology were investigated. High-energy neutron and Co-60 gamma-ray irradiation caused blue shifts in the wavelengths of micro-ring resonators and Mach-Zehnder interferometers. The devices with SiO2 upper cladding layer exhibited strong tolerance to irradiation.
Article
Engineering, Electrical & Electronic
K. V. Akshita, Dhandapani Dhanabalan, Rajendran Hariharan, Sridharan Moorthy Babu
Summary: Beta-Ga2O3 single crystals were successfully grown using OFZ technique with compressed dry air as growth atmosphere. The structural variations and optical properties of the irradiated wafers were analyzed using XRD, Raman spectroscopy, UV-Vis spectroscopy, and photoluminescence measurements. The study reveals the potential application of as-grown beta-Ga2O3 in harsh environments.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Tong Jin, Yuting Liu, Yan Xiong, Jincong Pang, Haodi Wu, Shunsheng Yuan, Ling Xu, Zhiping Zheng, Jiang Tang, Guangda Niu
Summary: This study presents a method to enhance the high-voltage stability of CsPbBr3 single crystals by surface polishing, passivation, and using a carbon electrode. These measures effectively reduce leakage current amplification and stability reduction, while improving the radiation detection capability of the device.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nuclear Science & Technology
I. I. Orlovskiy, E. N. Andreenko, K. Yu Vukolov
Summary: Flint glasses intended for use in ITER's optical diagnostics were tested in a nuclear reactor and showed resistance to fast neutron fluences. Two candidate flint types were irradiated in a gamma source and demonstrated no significant transient absorption, proving their suitability for diagnostic optics in ITER.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Dongil Ho, Sunwoo Choi, Hyunwoo Kang, Byungkyu Park, Minh Nhut Le, Sung Kyu Park, Myung-Gil Kim, Choongik Kim, Antonio Facchetti
Summary: Solution-processed metal-oxide thin-film transistors (TFTs) with different metal compositions were investigated for radiation hardness against ionizing radiation exposure. The amorphous zinc-indium-tin oxide (Zn-In-Sn-O or ZITO) was found to be an optimal radiation-resistant channel layer of TFTs due to its structural plasticity, defect tolerance, and high electron mobility. In situ irradiation experiments revealed three degradation mechanisms, including increase in channel conductivity, charge buildup in the interface and dielectric, and trap-assisted tunneling in the dielectric. By employing a radiation-resistant ZITO channel, a thin SiO2 dielectric, and a passivation layer, oxide-based TFTs demonstrated excellent stability under real-time gamma-ray irradiation.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Hans de Brouwer
Summary: This article compares the effects of x-ray and gamma radiation on the mechanical properties and color of five different engineering resins commonly used in medical devices. The study shows that both types of radiation have similar effects on the materials at the same dose. However, the impact of radiation on the tensile and impact test results is minimal except for the stress at yield point for polycarbonate. Color is strongly influenced by radiation, but a radiation stabilized polycarbonate with color compensation technology can be used to produce sterilized parts with a neutral appearance.
RADIATION PHYSICS AND CHEMISTRY
(2022)
Article
Engineering, Electrical & Electronic
Jheng-Yi Jiang, Chen-Xuan Tu, Jia-Wei Hu, Der-Sheng Chao, Chih-Fang Huang
Summary: The experimental results show that the 3.3 kV class 4H-SiC double-implanted MOSFET has excellent radiation hardness against gamma rays, outperforming Si insulated gate bipolar transistors (IGBTs) under the same conditions.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Jing Wang, Leidang Zhou, Xing Lu, Liang Chen, Zimin Chen, Xinbo Zou, Gang Wang, Boming Yang, Xiaoping Ouyang
Summary: In this study, ultrafast X-ray detectors were fabricated using a high resistivity unintentionally-doped epsilon-Ga2O3 film grown on sapphire by metal-organic chemical vapor deposition (MOCVD). The detector exhibited low dark current and high sensitivity, with stable and repeatable transient response under switching X-ray illumination. Furthermore, the detector achieved pulsed X-ray detection with a narrow time resolution. These results demonstrate the great potential of MOCVD-grown high-resistivity epsilon-Ga2O3 film for ultrafast X-ray detection.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Marilou Cadatal-Raduban, Kohei Yamanoi, Jiri Olejnicek, Michal Kohout, Seiya Kato, Yusuke Horiuchi, Tomoki Kato, Yu Haoze, Nobuhiko Sarukura, Shingo Ono
Summary: Titanium dioxide (TiO2) thin films can serve as photoconductive detectors of vacuum ultraviolet (VUV) radiation, and their performance can be enhanced after gamma ray irradiation. While an initial decrease in photocurrent is observed after irradiation, subsequent recovery of defects leads to a significant increase in photoconductivity.
Article
Engineering, Electrical & Electronic
Youngbin Yoon, Sunjae Kim, In Gyu Lee, Byung Jin Cho, Wan Sik Hwang
Summary: Polycrystalline n-type beta-Ga2O3 thin films with a thickness of 100 nm were successfully fabricated using sputtering and spin-on-glass Sn-doping techniques. These thin films were utilized as an active layer for power electronics and ultraviolet optoelectronics, showing high breakdown voltages and suitability for solar-blind photodetectors.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Optics
Jiawen Chen, Huili Tang, Zhiwei Li, Zhichao Zhu, Mu Gu, Jun Xu, Xiaoping Ouyang, Bo Liu
Summary: Beta-Ga2O3 semiconductor crystal has a wide band gap and high radiation resistance, making it suitable for applications in medical imaging, radiation detection, and nuclear physics experiments. A high-performance X-ray detector based on Fe-doped beta-Ga2O3 crystal has been demonstrated, showing high resistivity, short response time, high sensitivity, and a high signal-to-noise ratio, indicating great potential for X-ray radiation detection.
Article
Biology
Pamela Sinha, Kantha Devi Arunachalam, Santhosh Kumar Nagarajan, Thirumurthy Madhavan, Arumugam R. Jayakumar, Mohamed Saiyad Musthafa
Summary: Freshwater fish Pangasius sutchi was used as a vertebrate model to study the radioprotective effects of Gymnema sylvestre leaves extract and its bioactive compound Gymnemagenin compared to Amifostine. Results showed that Gymnema sylvestre had a similar antioxidant profile to Amifostine in reducing oxidative stress and promoting cell cycle progression.
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
(2022)
Review
Physics, Applied
Zeng Liu, Weihua Tang
Summary: This article discusses the recent progress of Ga2O3-based Schottky photodiodes and provides suggestions for Schottky metal selection, interfacial barrier modulation, space electric field adjustment, energy band engineering, and improvement of photodetection performance, aiming to promote the further development of deep-ultraviolet photodetection in the near future.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Construction & Building Technology
Totsawat Daungwilailuk, Chadet Yenchai, Wisarute Rungjaroenkiti, Phoonsak Pheinsusom, Chinnapat Panwisawas, Withit Pansuk
Summary: The present study aims to analyze the performance of concrete containing local minerals, barite and cut steel bars, in protecting against gamma-ray and fast-neutron radiation. The results show that using barite as aggregates can increase the radiation shielding capability, as well as the strength and density of specimens. Additionally, using cut steel bars as an additive material significantly enhances the attenuation coefficients of gamma-rays and neutrons.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Hong Nhan Tran, Chan Beom Park, Jin Hee Lee, Jung Hwa Seo, Jin Young Kim, Seung-Hwan Oh, Shinuk Cho
Summary: This study presents a solution-processable and annealing-free SnO2 nanoparticle layer for the electron transport layer in organic solar cells. The use of γ-ray irradiation disrupts the bonding between surfactant ligands and SnO2 nanoparticles, eliminating the need for high-temperature postannealing. The treated SnO2 nanoparticles offer comparable efficiency to conventional ones without postannealing and light-soaking effect, providing a promising and cost-effective solution for future flexible solar cells.
Article
Engineering, Electrical & Electronic
Masayuki Tsutsumi, Tatsuya Meguro, Akinori Takeyama, Takeshi Ohshima, Yasunori Tanaka, Shin-Ichiro Kuroki
Summary: Radiation-hardened CMOS image sensors (CIS) with 4H-SiC photosensors and APS-type circuits were developed and demonstrated. The 4H-SiC photodiodes had a dark current of <2 nA/cm(2), and their spectral sensitivity was evaluated from 200 nm to 400 nm. The photosensors showed a maximal quantum efficiency of 63% at 270 nm and high responses to UV light. After exposure to 2 MGy irradiation, the APS-type photosensors still functioned with a dark current of 25 nA/cm(2).
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Physics, Multidisciplinary
Daniil M. Lukin, Melissa A. Guidry, Joshua Yang, Misagh Ghezellou, Sattwik Deb Mishra, Hiroshi Abe, Takeshi Ohshima, Jawad Ul-Hassan, Jelena Vuckovic
Summary: This study reports on the integration of near-transform-limited silicon vacancy (VSi) defects into microdisk resonators fabricated in a CMOS-compatible 4H-silicon carbide-on-insulator platform. It demonstrates a single-emitter cooperativity of up to 0.8 and optical superradiance from a pair of color centers coupled to the same cavity mode. The effect of multimode interference on the photon scattering dynamics from this multiemitter cavity quantum electrodynamics system is investigated. These results are crucial for the development of quantum networks in silicon carbide and bridge the classical-quantum photonics gap by uniting optically coherent spin defects with wafer-scalable, state-of-the-art photonics.
Article
Nanoscience & Nanotechnology
Shingo Sotoma, Hiroshi Abe, Yohei Miyanoiri, Takeshi Ohshima, Yoshie Harada
Summary: In this study, methods for controlling the physicochemical properties of SiC nanoparticles were developed, including dispersion, surface coating, functionalization, and selective labeling of biomolecules. A thermal oxidation chemical-etching method was successfully developed to deaggregate and produce a high yield of dispersed, metal-contaminant-free SiC nanoparticles. Additionally, controllable thickness polydopamine and excellent dispersity polyglycerol coatings were demonstrated. Furthermore, a single-pot method was developed for selective labeling of CD44 proteins on cell surfaces through biotin-mediated immunostaining. The methods developed in this study are of great importance for the application of SiC nanoparticles in biomedical research and will greatly accelerate their development and potential applications in bioimaging and biosensing.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Tetta Suzuki, Yuichi Yamazaki, Takashi Taniguchi, Kenji Watanabe, Yusuke Nishiya, Yu-ichiro Matsushita, Kazuya Harii, Yuta Masuyama, Yasuto Hijikata, Takeshi Ohshima
Summary: In this study, two thermal treatment methods were used to successfully generate negatively charged boron vacancies (V (B) (-)) in hexagonal boron nitride with superior spin properties. Both methods improved the signal-to-noise ratio of the optically detected magnetic resonance signal by a factor of 4. Furthermore, the crystal distortion reflected by the zero-field splitting parameter E significantly reduced after irradiation above 650 degrees C. These findings indicate that thermal treatment is an effective method for a V (B) (-) based quantum sensor.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
C. T. -K. Lew, V. K. Sewani, N. Iwamoto, T. Ohshima, J. C. Mccallum, B. C. Johnson
Summary: Spin defects in solid-state sensors are investigated for their magnetic sensitivity, with potential applications in various industries. The study utilizes a silicon carbide pn-junction diode to detect a spin defect ensemble and enhance the baseline sensitivity through the hyperfine-induced spin-mixing effect observed at zero magnetic field. Additional electron-hole pairs are generated through above bandgap optical excitation, and a balanced detection scheme is implemented to reject common-mode noise, achieving an ultimate sensitivity of 30 nT/root Hz. Both techniques greatly enhance the magnetic sensitivity of the device by a total factor of approximately 24, paving the way for sub-nanotesla magnetic field sensitivities with electrical detection.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Tamotsu Okamoto, Fumiya Furumaki, Eiku Sato, Ippei Isogai, Yuji Kurimoto, Yasuki Okuno, Mitsuru Imaizumi, Masafumi Akiyoshi, Takeshi Ohshima
Summary: In this study, the effects of He ion and electron beam irradiation on substrate-type CdTe solar cells for detecting alpha and beta radiation were investigated. The induced current in the CdTe solar cell dosimeter increased proportionally with He ion current, indicating its potential for alpha radiation detection. The induced current in the dosimeter also showed proportionality to electron flux, with sensitivity depending on electron energy. Furthermore, the substrate-type CdTe solar cell dosimeter demonstrated sufficient resistance to electron beam irradiation, with no significant degradation in short-circuit current observed.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Rie Togashi, Ken Goto, Masataka Higashiwaki, Yoshinao Kumagai
Summary: Thermodynamic analyses were performed to study the growth of group-III sesquioxides by ozone and plasma-assisted MBE. The driving force for III2O3 growth increased with increasing input partial pressure of the group-III metal under O-rich conditions, but decreased under group-III-metal-rich conditions. This decrease was caused by the formation of Ga2O or In2O during growth. Ga and In droplets formed at low temperatures, while Al droplets were formed at high temperatures, with the growth order being c-In2O3 < ss-Ga2O3 << alpha-Al2O3.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Shu Motoki, Shin-ichiro Sato, Seiichi Saiki, Yuta Masuyama, Yuichi Yamazaki, Takeshi Ohshima, Koichi Murata, Hidekazu Tsuchida, Yasuto Hijikata
Summary: In this study, the potential of V-Si(-) defects for magnetic sensors operating at high temperatures was demonstrated, with the resonance frequency of the ground level being independent of temperature, indicating the possibility of calibration-free magnetic sensors in temperature-varying environments. The results also showed a linear relationship between magnetic sensing sensitivity and V-Si(-) concentration.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Zhenwei Wang, Takahiro Kitada, Daiki Takatsuki, Jianbo Liang, Naoteru Shigekawa, Masataka Higashiwaki
Summary: In this study, p-Si/n-Ga2O3 and p(+)-Si/n-Ga2O3 heterostructures were fabricated using surface-activated bonding technique, and their electrical properties were investigated. Current density-voltage measurement before and after thermal annealing at 450 ? showed a significant increase in current density after annealing, which was attributed to thinning of the intermediate layer formed during the bonding process. Distinctive two-stage capacitance-voltage characteristics were observed for p-Si/n-Ga2O3 heterostructures, and numerical calculation considering the effect of two-dimensional electron gas formed at the heterointerface reproduced these characteristics well. These results indicate that Ga2O3-based p-n heterostructures with good interface properties and large-area uniformity can be fabricated using surface-activated bonding.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Tihomir Knezevic, Eva Jelavic, Yuichi Yamazaki, Takeshi Ohshima, Takahiro Makino, Ivana Capan
Summary: In this study, boron-related defects in low-doped n-type 4H-SiC semitransparent Schottky barrier diodes (SBDs) were investigated using minority carrier transient spectroscopy (MCTS). Boron, introduced during chemical vapor deposition (CVD) crystal growth, led to the presence of shallow (B) and deep boron (D-center) defects, with concentrations as high as 1 x 10(15) cm(-3). Despite the higher concentration of boron compared to nitrogen doping, the steady-state electrical characteristics of the n-type 4H-SiC SBDs remained unaffected.
Article
Chemistry, Physical
Robert Bernat, Tihomir Knezevic, Vladimir Radulovic, Luka Snoj, Takahiro Makino, Takeshi Ohshima, Ivana Capan
Summary: We investigated the impact of large-area 4H-SiC Schottky barrier diodes on the radiation response to ionizing particles. Two diode areas, 1 mm x 1 mm and 5 mm x 5 mm, were compared. We utilized (LiF)-Li-6 and (B4C)-B-10 films as thermal neutron converters on top of the diodes. A thermal neutron efficiency of 5.02% was achieved with (LiF)-Li-6, which is among the highest reported efficiencies. Additionally, a temperature-dependent radiation response to alpha particles was presented, with neutron irradiations conducted in a JSI TRIGA dry chamber and an Am-241 wide-area alpha source used for testing.
Article
Physics, Applied
Hiroki Morishita, Naoya Morioka, Testuri Nishikawa, Hajime Yao, Shinobu Onoda, Hiroshi Abe, Takeshi Ohshima, Norikazu Mizuochi
Summary: In this study, positive contrast in photocurrent detected magnetic resonance (PDMR) of nitrogen-vacancy (N-V) centers in diamond is observed. The sign of the PDMR contrast depends on the difference in the photocurrent generated from the excited states and the metastable state of N-V centers. Additionally, noise suppression using a phase-cycling-based noise-canceling technique is introduced to achieve electrically detected ac magnetic field sensing with a sensitivity of 29 nT Hz-1/2.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Multidisciplinary
Islay O. O. Robertson, Sam C. C. Scholten, Priya Singh, Alexander J. J. Healey, Fernando Meneses, Philipp Reineck, Hiroshi Abe, Takeshi Ohshima, Mehran Kianinia, Igor Aharonovich, Jean-Philippe Tetienne
Summary: Detecting magnetic noise from small quantities of paramagnetic spins is achieved using spin defects in hexagonal boron nitride (hBN). Negatively charged boron vacancy defects are created in ultra-thin hBN nanoflakes, and the longitudinal spin relaxation time (T1) is measured. By decorating the dry hBN nanopowder with paramagnetic Gd3+ ions, a clear T1 quenching under ambient conditions is observed, indicating the presence of added magnetic noise. Spin measurements, including T1 relaxometry, can also be performed using solution-suspended hBN nanopowder. These findings demonstrate the potential and versatility of hBN quantum sensors for various sensing applications and pave the way towards a truly 2D, ultrasensitive quantum sensor.
Editorial Material
Physics, Applied
Khalid Hattar, Rudy J. M. Konings, Lorenzo Malerba, Takeshi Ohshima
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Coatings & Films
Takumi Ohtsuki, Masataka Higashiwaki
Summary: We systematically studied the relationship between the structural properties of (AlxGa1-x)(2)O-3 thin films grown on ss-Ga2O3 (010) substrates and the composition of Al. Crystal structure characterization was performed using X-ray diffraction, and surface morphology was observed using reflection high-energy electron diffraction and atomic force microscopy. Defects appeared on the surface and crystallinity began to degrade when the Al composition x exceeded approximately 0.16 in the 100-nm-thick thin films. The defects mainly developed along the [201] direction and slightly along the [001] direction as x increased. The boundary where the thin film quality changed was close to a critical thickness curve calculated using the Matthews-Blakeslee model assuming the slip system of <201>{10(2) over bar}.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
