Article
Crystallography
Hans-Georg Babin, Nikolai Bart, Marcel Schmidt, Nikolai Spitzer, Andreas D. Wieck, Arne Ludwig
Summary: Strategies for controlling growth parameters of local droplet etched GaAs quantum dots are presented in this study. Local QD density and emission wavelength can be managed through gradient material deposition, with regions of no light-emitting quantum dots separated from regions with strong luminescence. Additionally, controlling surface roughness can have a profound influence on emission characteristics.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Crystallography
K. Ben Saddik, A. F. Brana, N. Lopez, B. J. Garcia, S. Fernandez-Garrido
Summary: A wide range of n- and p-type doping levels in GaAs layers grown by chemical beam epitaxy can be achieved by adjusting the concentration or flux of diluted precursors. The incorporation of Si shows a linear dependence on the diluted-precursor flux, while C doping exhibits a superlinear behavior. Analysis by low-temperature photoluminescence spectroscopy suggests that diluting DTBSi or CBr4 with H-2 does not affect the electrical and optical properties of GaAs.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Energy & Fuels
Jiaping Wang, Peng Zhao, Ying Hu, Zhenhua Lin, Jie Su, Jincheng Zhang, Jingjing Chang, Yue Hao
Summary: The study focuses on optimizing all-inorganic perovskite/gallium arsenide tandem solar cells for potential space applications, achieving high power conversion efficiencies through adjustments in material thickness and doping concentrations. By achieving current matching, a significantly high efficiency is achieved in the 2-T configuration.
Article
Chemistry, Physical
Sabria Benrabah, Maxime Legallais, Pascal Besson, Simon Ruel, Laura Vauche, Bernard Pelissier, Chloe Thieuleux, Bassem Salem, Matthew Charles
Summary: This study explores the impact of several wet etchants commonly encountered in the microelectronic industry on the surface chemistry of GaN on silicon. Phosphoric acid treatment is found to significantly modify the surface and enable the recovery of the surface morphology. The study proposes a promising treatment method for the recovery of good quality GaN surfaces after dry etching.
APPLIED SURFACE SCIENCE
(2022)
Article
Crystallography
J. Iwan Davies, Andrew D. Johnson, Rodney I. Pelzel, Matthew D. Geen, Andrew M. Joel, Sung Wook Lim
Summary: III-V Compound Semiconductors, such as GaAs, InP, and GaN, are critical in supporting major technological revolutions and have high potential in the growing photonics industry. The mass-manufacturing of VCSEL-based devices, with improvements in cost-reduction and uniformity, is crucial in driving market growth in areas like 3D imaging, sensing, LIDAR applications, datacom, and industrial markets. The scalability to larger wafer diameters and in-situ process control are key challenges that need to be addressed for successful mass-production.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Materials Science, Multidisciplinary
Yikai Liao, Yixiong Zheng, Sang-Ho Shin, Zhi-Jun Zhao, Shu An, Jung-Hun Seo, Jun-Ho Jeong, Munho Kim
Summary: A monolithic integration strategy combining nanopillar antireflective structure and IGZO ultraviolet absorbing layer was proposed to enhance the ultraviolet-visible spectral responsivity of GaAs photodetectors. Significant responsivity enhancement was achieved, providing great promises for advanced GaAs-based ultraviolet-visible optoelectronics.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Crystallography
A. K. Verma, F. Bopp, J. J. Finley, B. Jonas, A. Zrenner, D. Reuter
Summary: This study compares different In-deposition schemes to achieve low-density self-assembled InAs quantum dots (QDs) on GaAs(100) substrates. The results show that homogeneous In deposition combined with annealing can achieve high-density QD distribution, while inhomogeneous deposition leads to lower and less reproducible densities of QDs.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Physical
Tomas Pejchal, Kristyna Bukvisova, Stella Vallejos, Daniel Citterberg, Tomas Sikola, Miroslav Kolibal
Summary: This study finds that pre-annealing ZnO in oxygen-poor conditions at low temperature enhances the diffusion of gallium into ZnO crystal lattice and that gallium acts as a reactant causing ZnO etching at diffusion temperatures, which can be a significant hurdle for the post-growth diffusion doping of ZnO nanostructures.
APPLIED SURFACE SCIENCE
(2022)
Article
Computer Science, Information Systems
Ahid S. Hajo, Sascha Preu, Leonid Kochkurov, Thomas Kusserow, Oktay Yilmazoglu
Summary: This study investigates fully integrated THz detectors using silver NWs as bridge contacts on highly doped GaAs and InGaAs layers, achieving improved performance at zero bias with a maximum cut-off frequency of 2.6 THz. Initial THz measurements suggest a responsivity of 0.81 A/W and low NEP value of 7 pW/root Hz at 1 THz.
Article
Crystallography
Yuichi Oshima, Shingo Yagyu, Takashi Shinohe
Summary: Etch pits were observed on a c-plane alpha-Ga2O3 epilayer using HCl gas etching, indicating a correlation between etch pit density and dislocation density. Gas-etching technique can effectively reveal dislocation distribution in a wide area, which is challenging to explore using traditional TEM.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Chemistry, Physical
Tomas Ceponis, Jevgenij Pavlov, Arunas Kadys, Augustas Vaitkevicius, Eugenijus Gaubas
Summary: Using wet etching method can improve the photoluminescence efficiency of MOCVD GaN materials and a blue luminescence band related to dislocations was discovered. The intensity of the blue luminescence band increases with longer wet etching exposure. The mechanisms of scintillation intensity and spectrum variations were examined through complementary photo-ionization and photoluminescence spectroscopy techniques, and the dislocation etch pits were analyzed by scanning techniques.
Article
Physics, Multidisciplinary
N. Carlon Zambon, Z. Denis, R. De Oliveira, S. Ravets, C. Ciuti, I. Favero, J. Bloch
Summary: By embedding quantum wells into semiconductor microresonators, tightly confined and mutually interacting excitonic, optical, and mechanical modes can coexist. In this study, we investigate the parametric modulation of optical and excitonic resonances by the interaction with a mechanical mode in the strong exciton-photon coupling regime. We find that the exciton-phonon coupling in semiconductors leads to a significant enhancement of polariton-phonon interactions, making it possible to achieve near-unity single-polariton quantum cooperativity on current semiconductor resonator platforms. We also analyze how polariton nonlinearities affect dynamical backaction, altering the ability to cool or amplify the mechanical motion.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Sabine Portal, Carles Corbella, Oriol Arteaga, Alexander Martin, Trinanjana Mandal, Bart Kahr
Summary: Optically anisotropic materials form through colloidal lithography were studied using SEM, confocal microscopy, and polarimetry. A hexagonal array mask made of sub-micron silica particles was created via Langmuir-Blodgett self-assembly, and the pattern was transferred onto silicon and glass substrates using ion beam etching. Gold films were then deposited onto the etched pillars to enhance optical properties. Polarimetric measurements showed that the etching directions influenced the linear birefringence and linear dichroism, with the chiroptical responses increasing with the angle of incidence.
Article
Chemistry, Physical
Nikola Papez, Rashid Dallaev, Pavel Kaspar, Dinara Sobola, Pavel Skarvada, Stefan Talu, Shikhgasan Ramazanov, Alois Nebojsa
Summary: This work focuses on the degradation of GaAs solar cells under continuous laser irradiation. The solar cells were exposed to intense light for two months, leading to changes in electrical characteristics and structural composition. Analysis using various techniques such as Raman spectroscopy and X-ray photoelectron spectroscopy confirmed displacement of titanium and aluminum atoms, as well as slight redistribution of oxygen bonds in the anti-corrosion coating.
Article
Materials Science, Multidisciplinary
Sabriye Acikgoz, Hasan Yungevis
Summary: The double cell electrochemical etching technique was used to study the evolution of surface morphology during the etching of p-type gallium arsenide (GaAs). It was found that transparent oxide structures of arsenic trioxide (As2O3) and gallium oxide (Ga2O3) can be grown on the GaAs surface under certain etching conditions. The formation of oxide structures was explained in terms of anodic dissolution and oxidation process of GaAs substrate. These oxide structures have potential applications in high-performance optoelectronic devices.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
E. Vasile, M. Sima, A. Sima, C. Logofatu
MATERIALS RESEARCH BULLETIN
(2020)
Article
Materials Science, Multidisciplinary
Marcela Elisabeta Barbinta-Patrascu, Camelia Ungureanu, Nicoleta Badea, Mihaela Bacalum, Andrada Lazea-Stoyanova, Irina Zgura, Catalin Negrila, Monica Enculescu, Cristian Burnei
Article
Biochemistry & Molecular Biology
Monica Daescu, Adelina Matea, Catalin Negrila, Constantin Serbschi, Alina C. Ion, Mihaela Baibarac
Article
Chemistry, Physical
N. C. Zoita, M. Dinu, A. E. Kiss, C. Logofatu, M. Braic
Summary: The hybrid DCMS / HiPIMS method was found to improve the structural and electrical properties of TiC thin films compared to the films grown using R-DCMS, with the former exhibiting better resistivity values.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Ashwani K. Sharma, Danhong Huang, Erin Vaughan, Petre C. Logofatu, Thomas J. Rotter, Madeleine L. Naudeau
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2020)
Article
Materials Science, Ceramics
Anuraag Gaddam, Amarnath R. Allu, Hugo R. Fernandes, George E. Stan, Catalin C. Negrila, Atul P. Jamale, Francois O. Mear, Lionel Montagne, Jose M. F. Ferreira
Summary: The addition of vanadium in lithium silicate glass causes an increase in the polymerization of the silicate network while depolymerizing the overall glass structure, leading to expansion and increased ionic conductivity.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Multidisciplinary
V Mihalache, M. Secu, C. Negrila, V Bercu, I Mercioniu, A. Leca
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
Catalin Constantin Negrila, Daniela Predoi, Rodica V. Ghita, Simona Liliana Iconaru, Steluta Carmen Ciobanu, Mirela Manea, Monica Luminita Badea, Adrian Costescu, Roxana Trusca, Gabriel Predoi, George A. Stanciu, Radu Hristu, Laura Denisa Dragu, Coralia Bleotu, Andreea Groza, Ioana Cristina Marinas, Mariana Carmen Chifiriuc
Summary: In this study, Ag:HAp and Ag:HAp + D-3 thin films were prepared on Ti substrate using vacuum deposition method, and the effects of UV irradiation on the thin films were investigated for the first time. The results indicated a process of recovery of the thin film's properties under UV irradiation, leading to a more complex UVA rapid degradation process. Furthermore, antifungal assays showed that all samples exhibited antifungal properties, while cytotoxicity assays revealed no alterations in HeLa cell morphology after incubation with the thin films.
Article
Materials Science, Multidisciplinary
M. Sima, E. Matei, E. Vasile, A. Sima, N. Preda, C. Logofatu
Summary: The research results show that hematite nanowires grown on FTO/TiO2 substrate exhibit higher stability, density, and length compared to those grown on FTO substrate. The film of hematite on FTO substrate also demonstrated good uniform coverage and thickness.
Article
Polymer Science
Mihaela Baibarac, Luiza Stingescu, Malvina Stroe, Catalin Negrila, Elena Matei, Liviu C. Cotet, Ion Anghel, Ioana E. Sofran, Lucian Baia
Summary: A new method for obtaining PVC spheres coated with graphene oxide (GO) is reported, showing a transformation of PVC grains and inducing chemical changes. Raman scattering and FTIR spectroscopy studies indicate the appearance of new chemical bonds. The composite material has potential applications as a flame-retardant material.
Article
Nanoscience & Nanotechnology
Yasmin Esqueda-Barron, Angel Perez del Pino, Pablo Garcia Lebiere, Arevik Musheghyan-Avetisyan, Enric Bertran-Serra, Eniko Gyorgy, Constantin Logofatu
Summary: Research has shown that hybrid electrodes fabricated using laser processing technology exhibit excellent performance in electrochemical capacitor applications, significantly increasing the capacitance of the electrodes. In addition, asymmetric aqueous and solid-state ECs display excellent stability over tens of thousands of charge-discharge cycles. Building electrodes composed of graphene nanowalls and transition metal oxide, with the laser-induced crystallization and coating of metal oxide nanostructures on the surface of graphene nanowalls, has been proven to be an effective and feasible method.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Multidisciplinary Sciences
Ana-Maria Bratu, Cristina Popa, Mihaela Bojan, Petre Catalin Logofatu, Mioara Petrus
Summary: This research focuses on the evolution of various apple varieties over time and their applications in quality storage maintenance. Two methods, laser photoacoustic spectroscopy and multispectral imaging, were used to evaluate long-stored apples for sorting and degradation assessment. Results showed that the ethylene content decreased and the ethanol content increased over time, reflecting a potential degradation of the apples. The non-invasive, real-time inspection methods can help identify the beginning of the degradation process, improving sorting capabilities and maintaining quality and storability.
SCIENTIFIC REPORTS
(2021)
Correction
Nanoscience & Nanotechnology
Yasmin Esqueda-Barron, Angel Perez del Pino, Pablo Garcia Lebiere, Arevik Musheghyan-Avetisyan, Enric Bertran-Serra, Eniko Gyorgy, Constantin Logofatu
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
M. Sima, E. Vasile, N. Preda, A. Sima, E. Matei, C. Logofatu
Summary: Ferroelectric alpha-Fe2O3/BaTiO3 photoanodes were prepared and the influence of ferroelectric polarization on their photoelectrochemical performance was investigated. Results showed that positive poling improved photocurrent density, and different directions of ferroelectric polarization had a significant impact on the performance. Electrochemical impedance spectroscopy measurements confirmed the effect of ferroelectric polarization on charge transfer kinetics.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Pablo Garcia Lebiere, Angel Perez del Pino, Guillem Domenech Domingo, Constantin Logofatu, Immaculada Martinez-Rovira, Ibraheem Yousef, Eniko Gyorgy
Summary: The research focuses on investigating novel composite materials to improve the energy storage performance of electrochemical capacitors. By combining different types of materials, synergistic effects are crucial for enhancing performance. Through RIMAPLE technique, electrodes composed of a mixture of carbon nanoentities, graphene oxide, cerium, and manganese oxides were fabricated, showing excellent performance and stability in symmetric electrochemical capacitors.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Crystallography
Jianzheng Hu, Long Yan, Ning Zhou, Yao Chen, Xiaoni Yang, Lianqiao Yang, Shiping Guo
Summary: The effect and mechanism of carrier gas velocity, V/III ratio, and carrier gas velocity match on the growth rate of AlN were investigated in this study. The results showed that the growth rate of AlN initially increased with hydrogen flow rate, reached saturation, and then decreased monotonically. The turning point value depended on the equipment and process. By increasing the MO VM, the growth rate of AlN could be improved, but the uniformity deteriorated due to turbulence and loss of uniform boundary layer. High quality AlN films were successfully grown on nano-patterned sapphire substrates with improved crystalline quality and atomic smooth surfaces.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Tingting Ma, Yang Li, Kangning Sun, Qinglin Cheng, Sen Li
Summary: This study investigates the melting process and nucleation behavior of sodium crystals using molecular dynamics simulation. The results show good agreement between simulated and experimental values for the melting temperature, density, and radial distribution function of sodium. The diffusion coefficient of liquid sodium increases linearly with temperature, and the homogeneous nucleation rate of melting in superheated sodium crystal exponentially increases with temperature. The findings provide theoretical support for applications involving heat and mass transfer in sodium-related systems.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Hisato Nishii, Shintarou Iida, Akira Yamasaki, Takumi Ikenoue, Masao Miyake, Toshiya Doi, Tetsuji Hirato
Summary: Epitaxial V2O3 films were fabricated on sapphire substrates using mist chemical vapor deposition (mist CVD) method, eliminating the need for high vacuum conditions. The films can be grown on sapphire substrates even under atmospheric pressure, with the optimal growth temperature at 823 K. The films grown at 823 K exhibit a metal-insulator transition at approximately 155 K. The film on C-plane sapphire exhibits a lower transition temperature compared to those on R- and A-plane sapphire substrates.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Jani Jesenovec, Kevin Zawilski, Peter Alison, Stephan J. Meschter, Sambit K. Saha, Andrew J. Sepelak, Peter G. Schunemann
Summary: In this study, NiSb needles were successfully formed in InSb by manipulating the growth rate and adding NiSb. These needle structures in InSb can be used to tune the magnetoresistance of devices. Additionally, undoped InSb crystals demonstrated good infrared transmission at low growth rates.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
D. Joseph Daniel, P. Karuppasamy, H. J. Kim
Summary: The 2-amino 4-methyl pyridinium oxalate (2A4MPO) compound was synthesized and its crystal structure, functional groups, thermal stability, electrical properties, and third-order nonlinear optical properties were studied. The results demonstrate that the synthesized crystal has good structural integrity, thermal stability, and potential for third-order nonlinear optical applications.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
C. W. Lan
Summary: The past two decades have witnessed a significant transformation in solar silicon crystal growth, especially in the competition between multi-crystalline silicon (Multi-Si) and mono-crystalline silicon (Mono-Si). The demand for this crucial material has exponentially surged, with silicon solar panels capturing over 95% of the global PV market share. The advancements in crystal growth technology during this period have set historical benchmarks, with the market share shifting from high-performance multi-crystalline silicon (HPM-Si) to CZ silicon.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Peiyao Hao, Lili Zheng, Hui Zhang
Summary: A novel design of argon gas tube for removing impurities during silicon ingot growth was developed, and numerical simulations showed that it can effectively extract SiO.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Geetika Sahu, Chanchal Chakraborty, Subhadeep Roy, Souri Banerjee
Summary: This article discusses the novel fractal nature of hydrothermally synthesized MoS2 QDs. By adjusting the reaction time, the study found that the average size of QDs increases and then decreases with longer reaction times. STEM images indicate that shorter reaction times lead to sheet formation, while extended reaction times cause sheets to fragment into QDs.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Pengjian Lu, Wei Huang, Junjun Wang, Haitao Yang, Shiyue Guo, Bin Li, Ting Wang, Chitengfei Zhang, Rong Tu, Song Zhang
Summary: A systematic study on the tetramethylsilane-hydorgen (TMS-H-2) system for the deposition of pure single-crystal SiC by high-temperature chemical vapor deposition (HTCVD) method is conducted. The study investigates the effect of temperature, pressure, and H-2:TMS ratio on the deposition conditions and provides a theoretical basis and guidance for improving the quality and cost of industrial production of single-crystal SiC.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Xinyu Jiang, Liangliang Liu, Yanqing Liu, Yan Wang, Zhaoping Hou
Summary: Investigation on the preparation of anisometric templated textured high entropy or multi-element doped ferroelectric ceramics was conducted using A-site disordered niobate microcrystals. The effects of process parameters on the morphology and chemical composition were studied, and the photocatalytic properties of the microcrystals were evaluated.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Mobashsara Tabassum, Md. Ashraful Alam, Sabrina Mostofa, Raton Kumar Bishwas, Debasish Sarkar, Shirin Akter Jahan
Summary: In this study, high crystallinity copper nanoparticles were synthesized by altering the reaction medium at low temperatures. The results show that changing the reaction medium can reduce the surface energy of precursors and promote the formation of highly crystalline copper nanoparticles.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Ivan Bodnar, Vitaly V. Khoroshko, Veronika A. Yashchuk, Valery F. Gremenok, Mohsin Kazi, Mayeen U. Khandaker, Tatiana I. Zubar, Daria I. Tishkevich, Alex Trukhanov, Sergei Trukhanov
Summary: This work presents the production of single crystals of Cu2ZnGeSe4, a semiconducting quaternary compound, using a gas chemical method with iodine as a transporter. The phase state, crystal structure, and lattice constants of the synthesized samples were refined and determined. The band gap of Cu2ZnGeSe4 was calculated using transmission spectrum and it was found that the band gap increases by 12% with decreasing temperature in the range of 20-300 K.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Timur Malin, Igor Osinnykh, Vladimir Mansurov, Dmitriy Protasov, Sergey Ponomarev, Denis Milakhin, Konstantin Zhuravlev
Summary: The effect of growth temperature on the buffer leakage currents of GaN-on-Si layers was investigated. It was found that higher growth temperature results in lower leakage currents. The defects in GaN layers grown at different temperatures were studied using photoluminescence technique, and a correlation between leakage currents, structural perfection, and donor concentration in GaN-on-Si layers was established. It was also observed that reduced growth temperature leads to the formation of inversion domains.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Thi-Hoai-Thu Nguyen, Jyh-Chen Chen
Summary: The effect of heater power control on heat, flow, and oxygen transport for CCz crystal growth was studied. Shorter upper side heater design could improve crystal quality and growth, but with higher power consumption.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Peter Rudolph
Summary: This article presents an overview of selected contributions to the development of crystal growth technology by the Laudise Prize awardee 2023. It discusses various aspects such as shaped crystal growth, the correlation between melt structure and crystal quality, control of intrinsic defects and inclusions, prevention of dislocation cell patterns, and melt growth experiments under a travelling magnetic field.
JOURNAL OF CRYSTAL GROWTH
(2024)
