Article
Energy & Fuels
Mohammed A. Razooqi Alaani, Prakash Koirala, Puja Pradhan, Adam B. Phillips, Nikolas J. Podraza, Michael J. Heben, Robert W. Collins
Summary: Thin film CdTe superstrate solar cells are fabricated by sputtering starting from CdS/CdSe front layers deposited on transparent conductor coated glass. The performance of these devices is sensitive to fabrication details including temperature-time profile and is optimized by correlating cell parameters with effective thicknesses determined through mapping spectroscopic ellipsometry.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Optics
Michael O. Yokosuk, Thomas E. Tiwald, Danielle L. Saunders, Thomas A. Blake, Tanya L. Myers
Summary: A method combining spectroscopic ellipsometry and transmission spectroscopy is introduced for deriving the optical constants of organic powdered materials. Different forms of pellets of anhydrous lactose were used for measurements, with the final n/k values for lactose obtained in the end. Additionally, a simpler method was proposed for powders that do not press easily into pure pellets.
Article
Physics, Applied
Mathias Schubert, Sean Knight, Steffen Richter, Philipp Kuehne, Vallery Stanishev, Alexander Ruder, Megan Stokey, Rafal Korlacki, Klaus Irmscher, Petr Neugebauer, Vanya Darakchieva
Summary: We report on terahertz electron paramagnetic resonance generalized spectroscopic ellipsometry (THz-EPR-GSE) and its application in studying spin transitions in 4H-SiC. The technique eliminates the need for a cavity, allows independent scanning of field and frequency parameters, and does not require modulation. By using THz-EPR-GSE measurements, we can fully determine the polarization properties of spin transitions and obtain the g and hyperfine splitting parameters of coordinated nitrogen. The results show fundamental differences in measurements at positive and negative fields, providing additional information.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Rosalia Delgado Carrascon, Steffen Richter, Muhammad Nawaz, Plamen P. Paskov, Vanya Darakchieva
Summary: Thick GaN layers with low defect concentration are crucial for next-generation vertical power electronic devices. In this study, we propose a new approach to grow high quality GaN homoepitaxy using hot-wall MOCVD. We develop a low temperature GaN as an optimum nucleation scheme and provide a comprehensive picture of homoepitaxial growth on GaN templates and native substrates. We demonstrate the potential of hot-wall MOCVD to deliver high-quality GaN material for vertical power devices.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Crystallography
Aofeng Bai, Maria Hilse, Prasanna D. Patil, Roman Engel-Herbet, Frank Peiris
Summary: In-situ spectroscopic ellipsometry (SE) analysis provides more precise dielectric functions and thicknesses of multilayer heterostructures, allowing for detection of subtle changes during growth processes.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Optics
Wenjie Zhang, Zhaohui Zeng, Tao Cheng, Tianhao Fei, Zhiwei Fu, Xiaoyan Liu, Jingyi Zhang, Jia-Yue Yang
Summary: This study synthesized tantalum pentoxide thin films using the magnetron sputtering method, measured the ultraviolet-visible dielectric function at various temperatures, and investigated the influence of temperature on the dielectric function from first principles. Experimental results showed a significant temperature dependence of the dielectric function, which was confirmed by theoretical calculations. Additionally, molecular dynamics simulations predicted the temperature-dependent dielectric function and agreed well with the experimental measurements.
Article
Polymer Science
Barbara Hajduk, Pawel Jarka, Henryk Bednarski, Tomasz Tanski
Summary: This study used variable angle spectroscopic ellipsometry (VASE) and variable temperature spectroscopic ellipsometry (VTSE) to investigate the surface order and dielectric properties of P3HT:PC70BM blend films. The results showed that an ordered layer of PC70BM phase was formed on the surface of the blend films under thermal annealing.
Article
Crystallography
V. A. Shvets, D. V. Marin, I. A. Azarov, M. V. Yakushev, S. V. Rykhlitskii
Summary: In situ temperature control is crucial for obtaining highly crystalline HgCdTe layers by molecular beam epitaxy. Spectroscopic ellipsometry is used to measure the temperature by analyzing different regions of the ellipsometric spectra of the CdTe buffer layer. The temperature measurement accuracy is several degrees with a sensitivity reaching fractions of a degree. Changes in temperature and composition during growth can be determined by studying the kinetics of ellipsometric spectra.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Physical
Desman Perdamaian Gulo, Nguyen Tuan Hung, Tan-Ju Yang, Guo-Jiun Shu, Riichiro Saito, Hsiang -Lin Liu
Summary: This study investigated the optical properties of graphite single crystal at different temperatures using spectroscopic ellipsometry. The results showed that at room temperature, graphite exhibited wide spectral range in the ultraviolet energy region. The peak position shifted to lower energies and the intensity increased with increasing temperatures. The study also confirmed the presence of two resonant conditions in the ultraviolet energy region.
Article
Thermodynamics
Xinhua Tan, Sami H. Altoum, Hakeem A. Othman, Muhammed I. Syam, M. A. Salman, Awad Musa
Summary: Numerical technique was used in this article to evaluate the efficiency of a system involving wavy shapes of wall. The porous material was used between two wavy complex surfaces, and the working fluid was a nanofluid consisting of water and alumina nanoparticles. The equations were solved using CVFEM and good agreement with previous results was reported.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Optics
Jiri Vohanka, Vaclav Sulc, Ivan Ohlidal, Miloslav Ohlidal, Petr Klapetek
Summary: Two samples of silicon-single crystal substrates with randomly rough surfaces covered by native oxide layers were studied using angle-resolved scattering, spectroscopic reflectometry, and variable-angle spectroscopic ellipsometry. The power spectral density functions were determined by simultaneously processing the experimental optical data and modeled using exponentials of quadratic splines. The thicknesses of native oxide layers were also determined. The influence of roughness on reflectance and ellipsometry was described using a combination of scalar diffraction theory for low spatial frequencies and Rayleigh-Rice theory for high and moderate spatial frequencies. The roughness was separated into parts using a bound dependent on the wavelength of the incident light. The power spectral density functions determined by the optical method were compared with those determined by processing AFM scans.
Article
Crystallography
Maria Hilse, Xiaoyu Wang, Phoebe Killea, Frank Peiris, Roman Engel-Herbert
Summary: In-operando spectroscopic ellipsometry was utilized to study the optical properties of Bi2Se3 films grown on sapphire substrates in a MBE reactor. A refined dielectric model for Bi2Se3 was developed by analyzing SE spectra at different temperatures, enabling real-time monitoring of growth conditions and film thickness. This technique offers a reliable and universal approach for comparing growth conditions and improving reproducibility for Bi2Se3 based films and heterostructures.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Materials Science, Multidisciplinary
D. V. Likhachev
Summary: This paper presents a systematic approach using statistical estimators to optimize B-spline models for accurate modeling of material optical functions. The approach combines a specific knot allocation method with a selection strategy for the number of knots, replacing the traditional trial-and-error strategy.
Article
Materials Science, Multidisciplinary
Wenjie Zhang, Tianhao Fei, Tao Cheng, Chong Zheng, Yanbing Dong, Jia-Yue Yang, Linhua Liu
Summary: The UV-Vis optical constants of SrTiO3 are investigated in terms of temperature and doping effects, showing changes in absorption peak amplitudes and spectrum shoulders with temperature increase, as well as unconventional Urbach tails with Nb doping. The study combines experimental spectroscopic ellipsometry with first-principles calculations to elucidate the fundamental optical phenomena of SrTiO3-based heterostructures or devices.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Crystallography
Kazutada Ikenaga, Nami Tanaka, Taro Nishimura, Hirotaka Iino, Ken Goto, Masato Ishikawa, Hideaki Machida, Tomo Ueno, Yoshinao Kumagai
Summary: The effect of high temperature homoepitaxial growth of (010) beta-Ga2O3 layer by low pressure hot-wall metal-organic vapor phase epitaxy was investigated. The growth rate decreased and the growth mode changed as the growth temperature increased. A smooth, twin-free single-crystalline homoepitaxial layer with a structural quality equivalent to that of the substrate could be grown at 1000 degrees C. The grown layers were all n-type and showed an effective donor concentration approximately equal to the Si impurity concentration.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Physical
Qi-Wen Chen, Ze-Qing Guo, Jian-Ping Zhou
Summary: Multifunctional continuous solid solutions NFMTO-x were successfully synthesized via a one-step hydrothermal method by controlling the ratio of Mg and Fe. The NFMTO-x materials exhibited enhanced visible light response, effective adsorption and photocatalytic degradation of organic pollutants, CO2 methanation capability, and easy recyclability due to their magnetic properties. This research provides a significant multifunctional material for water purification.
APPLIED SURFACE SCIENCE
(2024)
Review
Chemistry, Physical
George E. Stan, Maziar Montazerian, Adam Shearer, Bryan W. Stuart, Francesco Baino, John C. Mauro, Jose M. F. Ferreira
Summary: Bioactive glasses have the ability to form strong bonds with tissues and release therapeutic ions. However, their biomechanical compatibility limits their use in load-bearing applications. The use of magnetron sputtering technology to fabricate BG coatings shows promise in improving their efficacy and potential for application.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Zhaoxuan Wang, Zhicheng Yan, Zhigang Qi, Yu Feng, Qi Chen, Ziqi Song, Meng Huang, Peng Jia, Ki Buem Kim, Weimin Wang
Summary: The corrosion behavior of Fe-60 and Fe-83 ribbons in 0.6 M NaCl was studied. Fe-60 exhibited a local corrosion mode and formed a stable passivation film with higher corrosion resistance, while Fe-83 showed a combination of local and global corrosion modes and had lower corrosion resistance. Controlling the precipitation of nanocrystalline phases and increasing the POx content in the passivation film significantly improved the corrosion resistance of Fe-based glassy alloys.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Hao-Kai Peng, Sheng-Yen Zheng, Wei-Ning Kao, Ting-Chieh Lai, Kai-Sheun Lee, Yung- Hsien Wu
Summary: This study investigates the effects of high energy/fluence proton radiation on the performance of HfZrOx-based FeFETs memory with different Zr content. The results show that the characteristics of FeFETs are influenced by proton radiation, and the extent of the influence depends on the Zr content. FeFETs with 50% Zr content exhibit minimal changes in memory window and demonstrate good endurance and retention performance.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Zongyi Yue, Guangyi Wang, Zengguang Huang, Sihua Zhong
Summary: In this study, AZO and ITO films were successfully tuned as excellent passivation layers for c-Si surfaces, achieving effective minority carrier lifetime and outstanding optical properties through the optimization of annealing temperature and interfacial silicon oxide.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Martin Hruska, Jan Kejzlar, Jaroslav Otta, Premysl Fitl, Michal Novotny, Jakub Cizek, Oksana Melikhova, Matej Micusik, Peter Machata, Martin Vrnata
Summary: This paper presents a detailed study on the hydrogen sensing capabilities of highly nanoporous black gold films. The films exhibit fast response and recovery times at low temperatures. Different levels of nanoporosity were prepared and tested to investigate the sensing properties, and it was found that nanoporous black gold is suitable for hydrogen sensing. The sensitivity of the film depends on its nanoporosity.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Yupu Wang, Gaofeng Teng, Chun To Yiu, Junyi Zhu
Summary: In the study of BM-SCO and HSCO thin films, it was found that H vacancies tend to prefer sites near the external surface or oxygen vacancy channels (OVCs), while H interstitials prefer sites of oxygen on a layer that contains six-fold coordinated Co. These findings not only enrich the understanding of complex surface phenomena of defect formation but also provide an explanation for the reversibility during phase transformation.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Jiafeng Lu, Linping Teng, Qinxiao Zhai, Chunhua Wang, Matthieu Lancry, Ye Dai, Xianglong Zeng
Summary: In this study, we achieved full control of fiber nanograting orientation by manipulating laser polarization, and tailored space variant fiber nanogratings, which expanded the diversity in fiber nanograting engineering.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Yibo Liu, Yujie Tao, Yue Liu, Qi Sun, Qinrong Lin, Kexin Kang, Qinghua Zhang, Qingjie Sun
Summary: This study investigates the wettability of the Ti-Cu-Fe multi-metal system, specifically the wetting behaviors of CuSi3 droplets on TC4 and 304SS plates. The results show that the CO2 + Ar gas atmosphere significantly affects interfacial mass transfer, thus influencing the wettability of the systems.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Jimei Liu, Fei Wang, Rong Guo, Yuqi Liu, Mengyu Zhang, Jaka Sunarso, Dong Liu
Summary: This study developed Co/MXene composites with anti-corrosion properties by varying the cobalt content. These composites exhibited remarkable electromagnetic absorption performance and high resistance to corrosion under various corrosive conditions. The study also revealed the mechanism of electron transfer from cobalt to MXene and the electromagnetic dissipation behavior originated from polarization loss alone.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Moujie Huang, Yongsong Ma, Jingbo Yang, Lingyun Xu, Hangqi Yang, Miao Wang, Xin Ma, Xin Xia, Junhao Yang, Deli Wang, Chuang Peng
Summary: Strong metal-support interactions (SMSIs) are important for enhancing catalytic activities and stability in thermal catalysis. This study demonstrates a method to create SMSIs in electrocatalysis using carbon nanotubes and Ru nanoparticles, resulting in excellent catalytic activity and stability.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Ravi Trivedi, Brinti Mondal, Nandini Garg, Brahmananda Chakraborty
Summary: This study explores the potential of biphenylene as a nanocarrier for the delivery of the anticancer drug cisplatin. It is found that biphenylene offers physical stability, rapid release rate, solubility, and bio-compatibilities compared to other nanocarriers. The adsorption of cisplatin on the surface of biphenylene involves charge transfer from cisplatin to biphenylene. The drug is shown to be released at body temperature in an acidic environment. Biphenylene also exhibits excellent cytotoxicity activity and cellular uptake of the drug. Overall, biphenylene shows promise as a potential nanocarrier for cisplatin delivery.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Hyun Jeong, Hyeong Chan Suh, Ga Hyun Cho, Rafael Salas-Montiel, Hayoung Ko, Ki Kang Kim, Mun Seok Jeong
Summary: In this study, a potential platform to enhance Raman scattering and increase the number of observable Raman modes in monolayer transition metal dichalcogenides (TMDs) was proposed. The platform consisted of large-scale arrays of gold micropillars (MPs), which were able to enhance the Raman intensity of TMDs and make difficult-to-detect Raman modes observable. The platform showed great industrial advantages and wide applicability due to its low cost, simple process, large controllable area, and short process time.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Yasir Abbas, Shafqat Ali, Sajjad Ali, Waqar Azeem, Zareen Zuhra, Haoliang Wang, Mohamed Bououdina, Zhenzhong Sun
Summary: In this study, FeOx@SPNO-C core-shell nanospheres as a catalyst for degradation of sulfamethoxazole (SMX) were successfully synthesized. The synergistic interaction between FeOx and SPNO-C, high carbon charge density, and the presence of C = O groups and N/Fe-Nx sites were found to be key factors for the enhanced degradation of SMX.
APPLIED SURFACE SCIENCE
(2024)
Article
Chemistry, Physical
Qiaoting Yang, Yuxiao Gong, Yan Qian, Zhou-Qing Xiao, Serge Cosnier, Xue-Ji Zhang, Robert S. Marks, Dan Shan
Summary: This study proposes a hierarchical confinement strategy to design Prussian blue nanoparticles (PB NPs) with satisfactory electrocatalytic ability and stability. The catalytic synthesis of PB NPs is achieved through a hydrothermal process, and the as-prepared PB@NH2MIL exhibits efficient electronic transmission and enhanced electrocatalytic properties.
APPLIED SURFACE SCIENCE
(2024)