Article
Physics, Applied
Zong-Tao Li, Jia-Yong Qiu, Jia-Sheng Li, Xue-Wei Du, Ze-Long Li, Hong-Wei Zhang
Summary: Patterned structures in PeLEDs, such as the SiO2-microcolumn pattern, can reduce optical loss and improve the external quantum efficiency. The increase in the number of patterned interfaces contributes to a decrease in optical loss, thanks to the scattering effect and the utilization of waveguide and surface plasmon polariton modes. A PeLED with a five-interface structure based on an SMP substrate demonstrated improved light outcoupling, suggesting a synergistic design for efficient devices with multi-interface patterns.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Denis Sakhno, Eugene Koreshin, Pavel A. Belov
Summary: The study focuses on the dispersion properties of an easy-to-manufacture metamaterial made of connected metallic wires, which supports longitudinal waves across a wide frequency band and exhibits unprecedentedly short wavelengths in comparison to the material's period.
Article
Engineering, Electrical & Electronic
Yuto Hirai, Yutaka Suzuki, Masayuki Morisawa
Summary: Humidity is an important indicator used in many fields, so the technology for its measurement is significant. We studied humidity sensors using a swellable polymer as the cladding material of plastic optical fibers (POFs). By changing the incident light from a single wavelength to two wavelengths and using dye doping, a humidity sensor with high sensitivity and an RH detection range of 10%-90% can be developed.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
Hui Ge, Chong Sheng, Shining Zhu, Hui Liu
Summary: The Unruh effect, a fascinating aspect of quantum fields in curved spacetime, remains a challenge for direct experimental detection of Unruh temperature. Gradient optical waveguides are proposed to achieve high effective Unruh temperature, but experimental realization is yet to be reported. This study uses a tapered fiber to simulate accelerated motion and obtains effective Unruh temperature, showing a dependence of leaky radiation on photon acceleration.
Article
Optics
Pavel Psota, Jan Kredba, Marek Stasik, Jakub Necasek, Ondrej Matousek, Vit Ledl
Summary: This paper presents a technique for measuring the thickness of optical elements using absolute wavelength scanning interferometry. The technique is based on the Fizeau interferometer and utilizes data from three different tunable laser diodes to achieve a long effective wavelength range and low measurement uncertainty. The method can measure the thickness of both flat optical elements and lenses with curved surfaces. It provides areal information and high angle sensitivity for precise alignment and reduces misalignment errors. The results have been validated and cross-tested with other techniques, and the technique can be easily modified to measure other essential parameters of optical elements, replacing multiple single-purpose measuring devices while maintaining high accuracy.
Article
Optics
Romain Ceolato, Killian Aleau, Lucas Paulien, Edmundo Reynoso-Lara, Matthew J. Berg
Summary: The study utilizes a supercontinuum laser and a spatial filter to measure two-dimensional small-angle light-scattering patterns for various microparticles. The measurements are performed at 13 wavelengths to demonstrate qualitative particle-material sensitivity and the multispectral capability of the device.
Article
Optics
Jinwei Song, Junwei Min, Xun Yuan, Yuge Xue, Chen Bai, Baoli Yao
Summary: A method for quantitatively measuring the refractive index and topography of transparent samples is proposed. The method utilizes quadriwave lateral shearing interferometry to obtain quantitative phase images at different wavelengths, and uses Cauchy's dispersion formula to independently calculate the refractive indexes and physical thickness distribution of the sample. No highly dispersive medium or manual operation is required. The measured refractive indexes can identify the composition of the sample in addition to its topography. Simulation and experimental results have confirmed the effectiveness and feasibility of the proposed method.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Physics, Particles & Fields
G. R. Araujo, L. Baudis, N. McFadden, P. Krause, S. Schoenert, V. H. S. Wu
Summary: This study investigates the optical parameters of tetraphenyl butadiene (TPB) and polyethylene naphthalate (PEN) as wavelength shifters in liquid argon (LAr). The absolute quantum efficiency (QE) of TPB and PEN in LAr is estimated using experimental measurements and simulations.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Optics
Zhuo Wang, Yao Liang, Jiaqi Qu, Mu Ku Chen, Mingjie Cui, Zhi Cheng, Jingcheng Zhang, Jin Yao, Shufan Chen, Din Ping Tsai, Changyuan Yu
Summary: This study demonstrates the precise control of light-matter interaction through plasmonic resonances empowered by bound states in the continuum (BICs). By exploiting BICs in the parameter space, sharp resonances with ultra-weak angular dispersion effect and polarization-independent performance are achieved on symmetric plasmonic metasurfaces. These results provide a way to achieve efficient near-field enhancement using focused light produced by high numerical aperture objectives.
PHOTONICS RESEARCH
(2023)
Article
Chemistry, Physical
Partha Kumbhakar, Ashim Pramanik, Shashank Shekhar Mishra, Raphael Tromer, Krishanu Biswas, Arup Dasgupta, Douglas S. Galvao, Chandra Sekhar Tiwary
Summary: Various strategies have been developed to trap photons inside living cells for high-contrast imaging. One such strategy is the use of 3D-printed biomimetic architecture with localized surface plasmon resonance (LSPR) promoter. This study compares optical confinement in natural and 3D-printed photonic architectures and demonstrates that the 3D-printed fish scale with atomically thin quasicrystals (QCs) outperforms other 2D materials in terms of image contrast.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Biology
Daniel Kage, Kerstin Heinrich, Konrad V. Volkmann, Jenny Kirsch, Kristen Feher, Claudia Giesecke-Thiel, Toralf Kaiser
Summary: The MAPS-FC method combines multi-angle light scatter detection with time-resolved pulse shape analysis for high-throughput cell characterization, bypassing the limitations of traditional flow cytometry. By utilizing wavelet transform and k-means clustering for data analysis, cell cycle stages of Jurkat and HEK293 cells were successfully identified without the need for fluorescent labeling.
COMMUNICATIONS BIOLOGY
(2021)
Article
Physics, Applied
J. Schlipf, F. Berkmann, Y. Yamamoto, M. Reichenbach, M. Veleski, Y. Kawaguchi, F. Moerz, J. W. Tomm, D. Weisshaupt, I. A. Fischer
Summary: We have designed silicon-compatible vertical Germanium pin photodiodes structured into all-dielectric metasurfaces. Fabricated on silicon-on-insulator wafers, our proof-of-principle metasurfaces show high spectral selectivity and absorption efficiencies comparable to bulk Germanium layers. The lateral geometry of our metasurface structures can be tailored to the target wavelength, enabling applications such as spectroscopy and hyperspectral imaging in a low-cost electronic-photonic integrated circuit.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Shiqing Dong, Chao Dong, Kesheng Shen, Yun Zheng, Jie Sun, Cheng Zhen, Haiyang Hu, Feng Zhang, Zhe Zhang, Hongchao Liu, Hai Lu
Summary: The article introduces a dual resonant metasurface that can independently modify the spectrum in the near-infrared and mid-infrared regions. The metasurface exhibits spectral regulation and is suitable for refractive index sensing and ultra-sensitive vibrational spectroscopy. With the characteristics of wavelength multiplexing and polarization-dependent switch, it can be used for protein recognition and trace detection, and is of great significance for developing high-performance sensors and integrated photonics sensors in the broadband infrared region.
Article
Chemistry, Multidisciplinary
Daniel Carrasco, Eva Nieto-Pinero, Manuel Alonso-Orts, Rosalia Serna, Jose M. San Juan, Maria L. No, Jani Jesenovec, John S. S. McCloy, Emilio Nogales, Bianchi Mendez
Summary: An accurate understanding of the optical properties of beta-Ga2O3 is crucial for its full potential in photonics applications, especially its dependence on temperature. Optical micro- and nanocavities created within microwires and nanowires using distributed Bragg reflectors (DBR) show promise for various applications. This study analyzed the effect of temperature on the anisotropic refractive index of beta-Ga2O3 using ellipsometry, obtaining temperature-dependent dispersion relations fitted to Sellmeier formalism. Micro-photoluminescence (mu-PL) spectroscopy of microcavities in Cr-doped beta-Ga2O3 nanowires showed a thermal shift in red-infrared Fabry-Perot optical resonances, mainly due to temperature variations in the refractive index. Comparisons with finite-difference time-domain (FDTD) simulations incorporating the temperature-dependent, anisotropic refractive index obtained from ellipsometry revealed similar shifts, with slightly larger values observed in mu-PL results. The thermo-optic coefficient was calculated.
Article
Optics
Daniele Pirone, Joowon Lim, Francesco Merola, Lisa Miccio, Martina Mugnano, Vittorio Bianco, Flora Cimmino, Feliciano Visconte, Annalaura Montella, Mario Capasso, Achille Iolascon, Pasquale Memmolo, Demetri Psaltis, Pietro Ferraro
Summary: By applying computational segmentation, the three-dimensional quantitative shape of a cell nucleus can now be accurately identified without fluorescent staining. This method avoids the difficulties or impossibilities associated with cell staining and allows for the extraction of specific intracellular structures.
Article
Chemistry, Physical
Doo San Kim, Yun Jong Jang, Ye Eun Kim, Hong Seong Gil, Hee Ju Kim, You Jin Ji, Hyung Yong Kim, In Ho Kim, Myoung Kwan Chae, Jong Chul Park, Geun Young Yeom
Summary: In this study, a dual exhaust system was implemented in a reactive ion beam etcher (RIBE) to control the radical flux relative to ion flux during the etching process. The additional exhausting of radicals through the inductively coupled plasma (ICP) source chamber decreased both the ICP source chamber pressure and the ratio of radical flux to ion flux. This control of the radical flux is believed to be beneficial for anisotropic etching of nanoscale features in the next generation RIBE.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Analytical
Ki Seok Kim, You-Jin Ji, Ki-Hyun Kim, Ji-Eun Kang, Albert Rogers Ellingboe, Geun Young Yeom
Summary: Low-hydrogen-containing amorphous silicon (a-Si) was successfully deposited at a low temperature using a 162 MHz VHF plasma system. The use of smaller multi-split electrodes resulted in a high ion density plasma, leading to a high deposition rate and uniformity. Increasing the RF power reduced the hydrogen content in the deposited silicon film. The a-Si could be crystallized through UV irradiation without the need for dehydrogenation. Transmission electron microscopy revealed that the a-Si deposited by the VHF plasma system had a nanocrystalline-like structure, which could be significantly increased in size with UV irradiation.
Article
Multidisciplinary Sciences
Won Oh Lee, Ki Hyun Kim, Doo San Kim, You Jin Ji, Ji Eun Kang, Hyun Woo Tak, Jin Woo Park, Han Dock Song, Ki Seok Kim, Byeong Ok Cho, Young Lae Kim, Geun Young Yeom
Summary: This study investigates fast and selective isotropic etching of SiNx over SiOy using CIF3/H-2 remote plasma in an inductively coupled plasma system. The addition of H-2 increases etching selectivity and reduces the etch rate of both oxide and nitride.
SCIENTIFIC REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Ki Seok Kim, Ji Eun Kang, Peng Chen, Sungkyu Kim, Jongho Ji, Geun Young Yeom, Jeehwan Kim, Hyun S. Kum
Summary: Epitaxial lift-off techniques are important for the fabrication of lightweight and flexible devices. This study presents a new approach, using direct growth of thick graphene on the target substrate followed by atomic layer etching, to improve the yield and quality of remote epitaxy.
Article
Chemistry, Multidisciplinary
Seunghwan Seo, Jeong-Ick Cho, Kil-Su Jung, Maksim Andreev, Ju-Hee Lee, Hogeun Ahn, Sooyoung Jung, Taeran Lee, Byeongchan Kim, Seojoo Lee, Juncheol Kang, Kyeong-Bae Lee, Ho-Jun Lee, Ki Seok Kim, Geun Young Yeom, Keun Heo, Jin-Hong Park
Summary: Multi-valued logic (MVL) technology has been reconsidered due to the need for greater power saving in current binary logic systems. This study reports a reconfigurable m-NDR device with electric-field-induced tunability of multiple threshold voltages. The m-NDR phenomenon is achieved by modulating the resistance of the ReS2 layer using electrical pulses. The reconfigurability of the device is demonstrated in MVL circuits composed of the m-NDR device and a load transistor.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Hee Ju Kim, Long Wen, Doo San Kim, Ki Hyun Kim, Jong Woo Hong, Won Jun Chang, Soo Namgoong, Dong Woo Kim, Geun Young Yeom
Summary: The etch characteristics of silicon trenches masked with various SiO2/Si3N4 pattern distances were investigated using different pulse modes in Ar/Cl-2 inductively coupled plasmas. The results showed that using synchronously and asynchronously pulse modes instead of continuous wave (CW) mode increased the selectivity between Si and the mask layer and reduced the etch rate differences between wide and narrow pattern distance patterns (ARDE). The improvements in etch selectivity and reduction of ARDE were attributed to the increased conduction of Cl radicals/byproducts and time separated etch cycle composed of Cl chemical adsorption and removal of chemisorbed species.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Hyun Woo Tak, Hye Joo Lee, Long Wen, Byung Jin Kang, Dain Sung, Jeong Woon Bae, Dong Woo Kim, Wonseok Lee, Seung Bae Lee, Keunsuk Kim, Byeong Ok Cho, Young Lea Kim, Han Dock Song, Geun Young Yeom
Summary: In this study, the effects of chemical branch structure on plasma characteristics and etch characteristics of high aspect ratio ACL patterned SiO2 were investigated using three isomers with the same chemical composition. The results showed that the chemical branch structure significantly influenced the plasma properties and etch characteristics, even with the same chemical composition.
APPLIED SURFACE SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Doo San Kim, Yun Jong Jang, Ye Eun Kim, Hong Seong Gil, Byeong Hwa Jeong, Geun Young Yeom
Summary: In this study, atomic layer etching (ALE) process was used to precisely etch Sn for the fabrication of next generation extreme ultraviolet (EUV) mask. Optimized ALE conditions were identified to control the etch thickness of Sn and achieve high etch selectivity over the capping layer Ru, with minimal physical and chemical damage.
Article
Chemistry, Physical
You Jin Ji, Hae In Kim, Ki Hyun Kim, Ji Eun Kang, Doo San Kim, Ki Seok Kim, A. R. Ellingboe, Dong Woo Kim, Geun Young Yeom
Summary: In this study, the characteristics of PEALD SiNx films deposited at low temperatures were investigated. The use of a floating multi-tile electrode resulted in films with higher growth rate, higher N/Si ratio, lower surface roughness, and higher conformality. The electrical properties of the SiNx films deposited with the floating multi-tile electrode also showed improvement.
SURFACES AND INTERFACES
(2022)
Article
Materials Science, Coatings & Films
Ye Eun Kim, Doo San Kim, Yun Jong Jang, Hong Seong Gil, Ho Seop Jeon, Jong Woo Hong, In Ho Kim, Cheol Kim, Jeong-Heon Park, Geun Young Yeom
Summary: Rf-biased reactive ion beam etching (RIBE) with a H-2:NH3 gas mixture was used to etch CoFeB and MgO in the magnetic tunnel junction (MTJ) layer of magnetic random access memory. The etch selectivity of MTJ materials was increased with H-2 percentage in the gas mixture, and the etch rates were highest between 2:1 and 1:1 ratio of H-2:NH3 due to the synergy effect of H-2 and NH3. High rf-biasing during RIBE increased etch rates but decreased etch selectivities, while small rf-biasing improved etch characteristics such as higher selectivity, improved anisotropy, and thinner sidewall residue. The addition of small rf-biasing increased chemical etching effect without increasing physical sputtering effect, and also eliminated substrate charging.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Engineering, Electrical & Electronic
Jong Woo Hong, Hyun Min Cho, Yu Gwang Jeong, Da Woon Jung, Yun Jong Yeo, Ji Eun Kang, Hee Ju Kim, Hyun Woo Tak, Geun Young Yeom, Dong Woo Kim
Summary: A study was conducted on the dry etching of indium tin oxide (ITO) using novel hydrocarbon gases mixed with Ar, such as ethane and propane. The results showed that these gases increased the etch rate and selectivity of ITO, and reduced dimensional loss. The etch residues formed during the process could be successfully removed using H2/Ar plasma.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Hyunseok Kim, Yunpeng Liu, Kuangye Lu, Celesta S. Chang, Dongchul Sung, Marx Akl, Kuan Qiao, Ki Seok Kim, Bo-In Park, Menglin Zhu, Jun Min Suh, Jekyung Kim, Junseok Jeong, Yongmin Baek, You Jin Ji, Sungsu Kang, Sangho Lee, Ne Myo Han, Chansoo Kim, Chanyeol Choi, Xinyuan Zhang, Hyeong-Kyu Choi, Yanming Zhang, Haozhe Wang, Lingping Kong, Nordin Noor Afeefah, Mohamed Nainar Mohamed Ansari, Jungwon Park, Kyusang Lee, Geun Young Yeom, Sungkyu Kim, Jinwoo Hwang, Jing Kong, Sang-Hoon Bae, Yunfeng Shi, Suklyun Hong, Wei Kong, Jeehwan Kim
Summary: Multiple compound semiconductor membranes can be produced from a single wafer by directly growing two-dimensional materials on III-N and III-V substrates and then harvesting each epilayer through layer-by-layer mechanical exfoliation. This high-throughput layer transfer technique eliminates time-consuming processes and has the potential to greatly reduce manufacturing costs. The atomic-precision exfoliation at the 2D interface allows for the recycling of wafers for subsequent membrane production.
NATURE NANOTECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Jong Woo Hong, Yeon Hee Kim, Hee Ju Kim, Hyun Woo Tak, Ki Deok Bae, Jeong Yub Lee, Hae Soo Bae, Yong Su Kim, Geun Young Yeom
Summary: TiO2 meta materials with high aspect ratio pillars of different widths were etched using various plasma techniques. The results showed that the etch rates decreased in the order of continuous wave, bias pulsing, synchronous pulsing, and asynchronous pulsing conditions. However, the etch selectivities over ACL and SiO2 and the aspect ratio dependent etching (ARDE) effect improved in that same order. The improvement in ARDE effect was attributed to the decreased compositional differences between wide and narrow TiO2 pattern areas, especially under the asynchronous pulse condition.
Article
Nanoscience & Nanotechnology
Jong Woo Hong, Hyun Woo Tak, Young Hun Choi, Hee Jung Kim, Dong Woo Kim, Geun Young Yeom
Summary: Adding 50% CF3I into C4F8/Ar/O-2 gas mixtures resulted in both high etch selectivity over mask materials and potentially reduced etch damage.
SCIENCE OF ADVANCED MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Ki Seok Kim, Ki Hyun Kim, Ji Eun Kang, Ju-Hee Lee, You Jin Ji, Geun Young Yeom
Summary: In order to solve the contact resistance issue at the interface between metal electrodes and 2D semiconductors, researchers successfully removed the top sulfur layer and achieved the transition from semiconductor to metal in a two-dimensional transition-metal dichalcogenide material. By atomic doping, they were also able to transform the material to the p-type state. This atomic rearrangement technology shows potential in overcoming the limitations of advanced 2D semiconductors in electronic and optoelectronic devices.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
