Article
Chemistry, Physical
M. Montes Bajo, J. Tamayo-Arriola, N. Le Biavan, E. Martinez Castellano, D. Lefebvre, M. Hugues, J-M Chauveau, A. Hierro
Summary: A method based on infrared reflectance spectroscopy is presented for determining the Mg content in ZnO/(Zn,Mg)O multiple quantum wells. The method relies on observing interface phonon-polaritons and fitting the reflectance spectra to a dielectric function model to determine the LO phonon frequency of (Zn,Mg)O barrier layers, which depends on Mg content. Compared to calibration via cathodoluminescence, a linear relationship is found between reflectance dip frequency and Mg content.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Yudi Nugraha Thaha, Ika Kartika, I. Nyoman Gede Putrayasa Astawa, Franciska Pramuji Lestari, Aprilia Eryani, Fendy Rokhmanto, Muhammad Satrio Utomo
Summary: The corrosion behavior of Mg5Zn and Mg7Zn alloys in ovalbumin solution is accelerated by the addition of Na2HPO4, leading to a more severe corrosion attack. The presence of Na2HPO4 decreases the charge transfer resistance and film resistance on the alloy surface, promoting passivation and increasing corrosion rate.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Physics, Applied
Brian Good, Tursun Ablekim, Imran S. Khan, Matthew O. Reese, Andriy Zakutayev, Wyatt K. Metzger
Summary: Different transparent conducting oxides (TCOs) were studied for their electro-optical characteristics under various atmospheres and annealing conditions, revealing that GMZO as an alternative to MZO exhibits higher stability and superior electron density improvement effects, making it suitable for semiconductor applications.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Naoomi Yamada, Mari Mizutani, Kenta Matsuura, Masataka Imura, Hidenobu Murata, Junjun Jia, Fumio Kawamura
Summary: Wurtzite-type MgxZn1-xSnN2 alloys are proposed as promising earth-abundant and tunable band gap semiconductors with the potential to be grown on GaN substrates. These alloys show green-light emissions and can be tuned from 1.5 to 2.3 eV by increasing the composition parameter x. Direct-gap semiconductors with band gaps in the range of 1.8 to 2.5 eV are highly anticipated for the development of green LEDs and high-efficiency tandem solar cells.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Physics, Condensed Matter
Abdesamed Benbedra, Hamza Abbassa, Abdelkader Boukortt, Roland Hayn, Said Meskine, El Habib Abbes
Summary: This article investigates the spontaneous polarization of nanomaterials, using the trigonal structure as a reference state and comparing it with the previous results using the zinc blende structure. The theoretical value of spontaneous polarization is obtained by calculating the basal stacking faults with periodic hexagonal supercells, and it is found to be very close to the experimental measurement.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
V. Sebastian Calderon, John Hayden, Steven M. Baksa, William Tzou, Susan Trolier-McKinstry, Ismaila Dabo, Jon -Paul Maria, Elizabeth C. Dickey
Summary: Ferroelectric wurtzites have the potential to revolutionize modern microelectronics. This study observed and quantified real-time polarization switching of ferroelectric wurtzite at the atomic scale. A polarization reversal model was proposed, providing an important first step for property engineering efforts.
Article
Physics, Applied
Sergiu Clima, Christopher Pashartis, Jasper Bizindavyi, Sean R. C. McMitchell, Michel Houssa, Jan Van Houdt, Geoffrey Pourtois
Summary: Density functional theory predicts a sharp decrease in stability, kinetic barrier for polarization reversal, and spontaneous polarization of a ScxAl1-xN wurtzite phase when the Sc:Al ratio nears 50:50. The same effect can be achieved through the application of tensile strain. Experimental results show a correlation between the resulting polarization reversal barrier and measured coercive fields, with highly textured films exhibiting polarization values close to theoretical predictions, while film thickness below 5 nm significantly impacts elastic properties.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Shan-Shan Wang, D. Huber, J. D. Poplawsky, G. S. Frankel
Summary: The study demonstrated that surface abrasion creates altered surface layers (ASLs) on various types of aluminum alloys, which have lower corrosion resistance. High temperature treatments can enhance the precipitation of eta phase in the ASL, leading to an increase in ASL breakdown potential by decreasing the zinc content in the ASL solid solution.
Article
Engineering, Electrical & Electronic
Akram Abdalla, Mati Danilson, Valdek Mikli, Sergei Bereznev
Summary: Ternary Zn(O,Se) films were grown using pulsed laser deposition, and their optical properties and energy band structure were investigated. The findings suggest that adjusting the conduction band alignment can reduce the barriers in solar cell structures.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Amalendu Bera, Sourav Chattopadhyay
Summary: A p-Si/Zn(Mg)O/ZnO/Zn(Fe)O heterostructure was fabricated and investigated for light-emitting diode applications. The results showed non-ideal diode behavior at room temperature, with specific spectral peaks and wavelength ranges observed.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Dakshinamurthy Sivakumar, Sathishkumar Mudedla, Seonghun Jang, Hyunjun Kim, Hyunjin Park, Yonwon Choi, Joongyo Oh, Sangwook Wu
Summary: This study investigated the interaction patterns of various PDE9 inhibitors in different metal systems, focusing on their non-bonded interactions with PDE9. The results provide insights into the mechanism of action of these inhibitors.
Article
Materials Science, Multidisciplinary
Michiaki Yamasaki, Zhiminig Shi, Andrej Atrens, Akito Furukawa, Yoshihito Kawamura
Summary: A highly corrosion resistant Mg-Zn-Y-Al alloy with a multimodal microstructure has been developed, showing orientation dependent corrosion behavior. The addition of aluminum facilitates the formation of a protective surface film.
Article
Multidisciplinary Sciences
Somayeh Solgi, Mir Saeed Seyed Dorraji, Seyyedeh Fatemeh Hosseini, Mohammad Hossein Rasoulifard, Ismael Hajimiri, Alireza Amani-Ghadim
Summary: Scientists have successfully synthesized nanoparticles of NiFe2O4, X-doped g-C3N4, and MTiO3 for use as absorption agents in nanocomposites. The optimal nanocomposite demonstrated high absorption rates in the high-frequency range and significantly increased attenuation constants in the X-band when novel nanoparticles were added as fillers.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Scott D. Midgley, Said Hamad, Keith T. Butler, Ricardo Grau-Crespo
Summary: This study demonstrates that a simple descriptor based on the Coulomb matrix eigenspectrum outperforms the cluster expansion in predicting total energy and bandgap energy in alloy configurational space. Furthermore, introducing non-linearity via gradient-boosted decision trees or neural networks based on the Coulomb matrix descriptor can further improve bandgap predictions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
David Stone, Somnath Koley, Sergei Remennik, Lior Asor, Yossef E. Panfil, Tom Naor, Uri Banin
Summary: In this study, luminescent wurtzite InP nanocrystals with narrow size distribution were successfully synthesized, showing highly resolved absorption spectrum and narrow emission line. Anisotropy measurements demonstrated polarized transitions directly reflecting the anisotropic wurtzite lattice of the nanocrystals.
Article
Chemistry, Multidisciplinary
Mao Wang, Ye Yu, Slawomir Prucnal, Yonder Berencen, Mohd Saif Shaikh, Lars Rebohle, Muhammad Bilal Khan, Vitaly Zviagin, Rene Hubner, Alexej Pashkin, Artur Erbe, Yordan M. Georgiev, Marius Grundmann, Manfred Helm, Robert Kirchner, Shengqiang Zhou
Summary: The occurrence of mid-infrared localized surface plasmon resonances (LSPR) in thin Si films hyperdoped with tellurium (Te) is demonstrated in this study. By fabricating two-dimensional arrays of micrometer-sized antennas in a Te-hyperdoped Si chip, the mid-infrared LSPR can be further enhanced and extended to the far-infrared range. This finding opens up the possibility of integrating plasmonic sensors with the on-chip CMOS platform, greatly advancing the mass manufacturing potential of high-performance plasmonic sensing systems.
Article
Materials Science, Multidisciplinary
Xinyi Xia, Nahid Sultan Al-Mamun, Chaker Fares, Aman Haque, Fan Ren, Anna Hassa, Holger von Wenckstern, Marius Grundmann, S. J. Pearton
Summary: This study used X-ray photoelectron spectroscopy to measure the valence band offsets of Al2O3 deposited on α-(AlxGa1-x)(2)O-3 alloys. The results showed that the band alignment was type I at lower Al contents and staggered at higher Al contents.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Philipp Storm, Susanne Selle, Holger von Wenckstern, Marius Grundmann, Michael Lorenz
Summary: Transparent, p-type semiconductor copper iodide (CuI) thin films were grown via pulsed laser deposition on SrF2(111) using water soluble sacrificial layers of sodium bromide (NaBr). The resulting CuI thin films are single crystalline with reduced surface roughness compared to epitaxial CuI grown with rotational domains on other templates. The CuI thin films were subsequently transferred onto glass using epoxy/glue and dissolution of NaBr in a water-vapor atmosphere.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Christian Thieme, Liliya Vladislavova, Katrin Thieme, Christian Patzig, Thomas Hoeche, Christian Ruessel
Summary: Noble metal silver can act as a nucleation agent in glass ceramics and has different effects on crystal growth. In BaO/SrO/ZnO/SiO2 glasses, silver forms metallic particles with plate-like morphology during thermal treatment, while alloying and subsequent decomposition are prerequisites for the formation of plate-like noble metal particles.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Physics, Condensed Matter
Evgeny Krueger, Volker Gottschalch, Gabriele Benndorf, Ron Hildebrandt, Ana Lucia Pereira, Michael S. Bar, Steffen Blaurock, Stefan Merker, Chris Sturm, Marius Grundmann, Harald Krautscheid
Summary: This study presents the epitaxial growth of AgxCu1-xI alloy layers and isolated small crystals on Al2O3 (0001) using the close distance sublimation (CDS) technique. Single-phase gamma-AgxCu1-xI thin films are obtained up to an Ag content of approximately 0.5, with the beta-phase also observed at higher Ag contents. The epitaxial relationships between the deposited AgxCu1-xI layers and the Al2O3 substrate, as well as the structure type, are discussed for different alloy compositions. Additionally, a method for depositing polycrystalline single-phase gamma-AgxCu1-xI thin films for Ag contents up to approximately 0.7 is presented based on the solid-state reaction of AgI layers on Al2O3 (0001) substrate with CuI. Furthermore, it is shown that the near-band-edge emission at 2 K is dominated by excitonic recombination, and the spectral position of the emission profile can be tuned by the alloy composition.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Jon Borgersen, Robert Karsthof, Vegard Ronning, Lasse Vines, Holger von Wenckstern, Marius Grundmann, Andrej Yu Kuznetsov, Klaus Magnus Johansen
Summary: Significant resistivity variations have been observed in oxides subjected to low ion doses, which cannot be explained by bulk defects. A comparative study of In2O3-based oxides revealed correlations between resistivity evolution, low ion doses, and UV illumination. The resistivity drops were attributed to oxygen desorption facilitated by irradiation/illumination, as confirmed by post-irradiation exposure to oxygen atmosphere.
Review
Materials Science, Coatings & Films
Laurenz Thyen, Daniel Splith, Max Kneiss, Marius Grundmann, Holger von Wenckstern
Summary: We introduce a new technique, MARS-PLD, for area-selective physical vapor deposition. By using a movable mask, we can selectively mask any desired area on a substrate to create multinary material composition gradients. We demonstrated the capabilities of this method by fabricating material gradients in (Mg,Zn)O thin films and on predefined two-dimensional patterns.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Nanoscience & Nanotechnology
Evgeny Krueger, Michael Seifert, Volker Gottschalch, Harald Krautscheid, Claudia S. Schnohr, Silvana Botti, Marius Grundmann, Chris Sturm
Summary: We studied the excitonic transition energy E-0 and spin-orbit split-off energy Delta(0) of gamma-AgxCu1-xI alloy thin films using reflectivity measurements at temperatures between 20 K and 290 K. The observed bowing behavior of the E-0 transition as a function of alloy composition is explained based on first-principles band structure calculations. The spin-orbit coupling increases with increasing Ag-content, and the temperature-dependent bandgap shift decreases with increasing Ag-content.
Article
Physics, Applied
Andreas Mueller, Sebastian Henn, Evgeny Krueger, Steffen Blaurock, Harald Krautscheid, Marius Grundmann, Chris Sturm
Summary: We report on the photoluminescence emission in copper iodide bulk single crystals induced by two- and three-photon absorption around 1.525eV. The non-linear optical processes were investigated through density-dependent, steady-state, and time-resolved photoluminescence spectroscopy. We observed that the photoluminescence intensity showed an almost parabolic behavior with the excitation power when the excitation energy corresponded to half of the bandgap energy. We also found a cubic contribution that increased with decreasing excitation energy. The ratio between the two- and three-photon absorption cross sections was determined to be approximately 10(-28) cm(2)s.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Condensed Matter
Marius Grundmann
Summary: This study revisits the problem of potential, electrical field, and charge density in a space charge region. Using the Boltzmann approximation, an analytical asymptotic solution is obtained. The exact solution can be found by numerically integrating an analytical function. A comparison is made with the popular abrupt (or depletion) approximation, and an analytical approximation is provided. The analytical approximation for potential, electrical field, and charge density in a space charge (depletion) region shows good agreement with the (numerically) exact solution.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Instruments & Instrumentation
Michael Lorenz, Holger Hochmuth, Holger von Wenckstern, Marius Grundmann
Summary: Pulsed laser deposition (PLD) is a highly flexible physical growth technique for thin films of functional materials. This article describes a relatively simple and reliable concept of PLD hardware that enables deposition on large areas (up to 4 inches in diameter) and tailored lateral and vertical composition spreads without the need for time-consuming hardware changes. Different PLD approaches have been implemented in various chambers by using specific and correlated computer-controlled movements of the target, substrate, and masks, along with an appropriate target phase composition.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Nanoscience & Nanotechnology
Fabian Schoeppach, Daniel Splith, Holger von Wenckstern, Marius Grundmann
Summary: In this study, metal-semiconductor field-effect transistor (MESFET) devices based on pulsed laser deposition (PLD) grown In2O3 thin films are reported. These devices exhibit on-off ratios exceeding 6 orders of magnitude and low sub-threshold swing values close to the thermodynamic limit. Oxygen plasma treatment and compensation doping with Mg are used to suppress the accumulation of electrons at the surface of In2O3, which is a major obstacle for its use as an active material in electronic devices.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Christian Thieme, Marc Dittmer, Thomas Hoeche, Markus Rampf, Christian Ruessel
Summary: Phase formation in glasses from the Na2O-Y2O3-SiO2-ZrO2 system was studied and the effects of thermal history were investigated. During slow cooling, a precipitate of apatite structure phase (NaY9Si6O26) was observed, whereas the remaining glassy phase was enriched in ZrO2. It was also found that fast cooling resulted in glass formation without instant crystallization. Subsequent heating led to the formation of an unknown phase at lower temperatures and NaYSi2O6 crystals at higher temperatures. Nucleation and crystal growth experiments showed the homogeneous formation of small ZrO2 particles within the samples.
Article
Materials Science, Multidisciplinary
Thomas Ruf, Stefan Merker, Frank Syrowatka, Philip Trempler, Georg Schmidt, Michael Lorenz, Marius Grundmann, Reinhard Denecke
Summary: This study focuses on the structural compatibility of perovskite BaTiO3 on garnet substrates Gd3Ga5O12 and Y3Fe5O12, with a particular emphasis on the growth behavior on different garnet orientations. It was found that BaTiO3 growth on the garnet (100) orientation showed good crystallinity, while growth on other orientations resulted in polycrystalline films.
MATERIALS ADVANCES
(2022)
