Article
Chemistry, Multidisciplinary
Camille Barbier, Ludovic Largeau, Noelle Gogneau, Laurent Travers, Christophe David, Ali Madouri, Dyhia Tamsaout, Jean-Christophe Girard, Guillemin Rodary, Hervei Montigaud, Christophe Durand, Maria Tchernycheva, Frank Glas, Jean-Christophe Harmand
Summary: This study investigates the nucleation of GaN nanostructures on graphene as growth substrates for semiconductors. By using plasma-assisted molecular beam epitaxy, the incubation time before the epitaxy of the first GaN islands is explored. It is found that graphene is modified after nitrogen plasma exposure, and C-N bonds are identified. The adhesion between graphene and GaN nanostructures is found to be strong due to the incorporation of pyridinic N atoms in the lattice. This work demonstrates the modification of a graphene monolayer before nucleation and growth of GaN nanowires becomes possible.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Vladimir G. Dubrovskii, Simon Escobar Steinvall, Virginie de Mestral, Rajrupa Paul, Jean-Baptiste Leran, Mahdi Zamani, Elias Z. Stutz, Anna Fontcuberta Morral
Summary: Selective area growth of Zn3P2 on InP provides high-quality semiconductor nanostructures made of earth-abundant elements. In the precoalescence stage, Zn3P2 emerges in the form of nanoislands and undergoes a shape transformation. The results are presented in dimensionless variables, allowing simultaneous understanding of islands grown in differently sized pinholes and for different growth times.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Bruno Daudin, Alexandra-Madalina Siladie, Marion Gruart, Martien den Hertog, Catherine Bougerol, Benedikt Haas, Jean-Luc Rouviere, Eric Robin, Maria-Jose Recio-Carretero, Nuria Garro, Ana Cros
Summary: The spontaneous growth of GaN nanowires in the absence of catalyst is controlled by Ga flux, with diffusion barriers causing an uneven distribution of Ga adatoms at the top surface leading to GaN accumulation in the periphery. This promotes the formation of superlattices in InGaN and AlGaN nanowires, while the presence of Mg enhances Al diffusion length along the sidewalls in AlN nanowires, inducing the formation of AlN nanotubes.
Article
Crystallography
Ana Bengoechea-Encabo, Steven Albert, Michael Niehle, Achim Trampert, Enrique Calleja
Summary: Two different arrays of GaN nanocolumns with different average diameters were selectively grown on GaN-buffered Si(0 0 1) substrates. The footprint of the nanocolumns plays an important role in the crystalline quality, despite the low quality of the GaN buffer layer. These results are significant for the integration of GaN-based nano-devices with conventional Si(0 0 1) electronics platform.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Chemistry, Physical
Henryk Turski, Pawel Wolny, Mikolaj Chlipala, Marta Sawicka, Anna Reszka, Pawel Kempisty, Leszek Konczewicz, Grzegorz Muziol, Marcin Siekacz, Czeslaw Skierbiszewski
Summary: Atomically thin metal adlayers are used as surfactants in semiconductor crystal growth, with the role of the adlayer in dopant incorporation in GaN being unexplored. Experimental study shows that the presence of atomically thin gallium or indium layers dramatically affects Ge incorporation in GaN, with indium surfactant layer promoting Ge incorporation while gallium surfactant layer promotes segregation of Ge to the surface. Understanding the role of surfactants is crucial for controlling GaN doping and achieving high n-type doping levels using Ge.
Article
Chemistry, Multidisciplinary
Talgat Shugabaev, Vladislav O. Gridchin, Sergey D. Komarov, Demid A. Kirilenko, Natalia V. Kryzhanovskaya, Konstantin P. Kotlyar, Rodion R. Reznik, Yelizaveta I. Girshova, Valentin V. Nikolaev, Michael A. Kaliteevski, George E. Cirlin
Summary: In this study, hybrid nanostructures based on InGaN nanowires with decorated plasmonic silver nanoparticles were investigated. It was found that plasmonic nanoparticles caused the redistribution of room temperature photoluminescence between short-wavelength and long-wavelength peaks of InGaN nanowires. The short-wavelength maxima decreased by 20%, while the long-wavelength maxima increased by 19%. This phenomenon was attributed to energy transfer and enhancement between different parts of the nanowires with varying In content and a proposed Frohlich resonance model was used to explain the enhancement effect.
Article
Nanoscience & Nanotechnology
T. Auzelle, M. Oliva, P. John, M. Ramsteiner, A. Trampert, L. Geelhaar, O. Brandt
Summary: The self-assembly of GaN nanowires on TiN(111) substrates is examined using SiN x patches as nucleation seeds. The density of the nanowires can be tuned by three orders of magnitude by varying the amount of pre-deposited SiN x , bridging the density regimes achievable by direct self-assembly with MBE or MOVPE. This approach has potential applications in tuning the density of III-V semiconductors grown on inert surfaces like 2D materials.
Article
Optics
Yuanpeng Wu, Yixin Xiao, Ishtiaque Navid, Kai Sun, Yakshita Malhotra, Ping Wang, Ding Wang, Yuanxiang Xu, Ayush Pandey, Maddaka Reddeppa, Walter Shin, Jiangnan Liu, Jungwook Min, Zetian Mi
Summary: Micro or submicron scale light-emitting diodes (mu LEDs) have been extensively studied as the next-generation display technology. However, achieving high stability and efficiency, submicron pixel size, and integration with CMOS electronics has remained a challenge. This study reports the successful growth of mu LEDs on silicon with stable, bright green emission, and negligible quantum-confined Stark effect. The use of AlGaN barriers effectively compensates for the strain within the active region, improving indium incorporation without compromising material quality. This research provides insights and a viable approach for high-performance mu LEDs on silicon.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
O. de Melo, M. Ramirez-Lopez, M. Perez-Caro, S. Gallardo-Hernandez, Y. L. Casallas-Moreno, M. Sanchez, J. Ortega, G. Santana, M. Behar, Y. Gonzalez, M. Lopez-Lopez
Summary: In this study, self-assembling of InxGa1-xN nanostructures under strong nitrogen-rich conditions on Si (111) substrates by molecular beam epitaxy was reported. The strain evolution and morphological changes of the films were monitored using in-situ analysis. Different nanostructures were observed depending on the In content, including nanocolumns and nanowalls. XRD and RBS measurements provided information about the indium concentration and composition of the films, and suggested phase separation at higher indium concentration. The morphology change from columnar surface arrangement to separated nanowalls as the indium content increases was discussed. A shift towards lower energies of the low temperature photoluminescence spectra with increased In concentration was observed.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
I Ohkubo, Z. Hou, J. N. Lee, T. Aizawa, M. Lippmaa, T. Chikyow, K. Tsuda, T. Mori
Summary: The closed-loop optimization of epitaxial titanium nitride thin-film growth was achieved using metal-organic molecular beam epitaxy (MO-MBE) technique combined with Bayesian machine learning, reducing the number of growth experiments. Epitaxial TiN thin films grown under the optimized conditions exhibited abrupt superconductor transitions above 5 K, showing a new efficient approach for developing less-studied materials. The combination of thin-film growth technique and Bayesian approach is expected to accelerate the development of automated operation of thin-film growth apparatuses.
MATERIALS TODAY PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Spencer McDermott, Ryan B. Lewis
Summary: Freestanding semiconductor nanowires have enabled new possibilities for semiconductor devices, allowing for geometries, material combinations, and strain states that were previously impossible. By studying the evolution of nanowires during asymmetric shell deposition, researchers have uncovered the underlying mechanisms of the bending process, guiding future experiments and paving the way for the manufacture of bent nanowire devices.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Vladimir V. Fedorov, Yury Berdnikov, Nickolay V. Sibirev, Alexey D. Bolshakov, Sergey V. Fedina, Georgiy A. Sapunov, Liliia N. Dvoretckaia, George Cirlin, Demid A. Kirilenko, Maria Tchernycheva, Ivan S. Mukhin
Summary: The study demonstrates highly controllable self-catalyzed growth of gallium phosphide (GaP) nanowires on template-free silicon substrates, achieving a high yield of vertical GaP nanowires with control over surface density. The approach also allows for independent control of GaP nanowire length and diameter, providing a new method for designing photonic and electronic devices at the nanoscale.
Article
Energy & Fuels
Arto Aho, Riku Isoaho, Marianna Raappana, Timo Aho, Elina Anttola, Jari Lyytikainen, Arttu Hietalahti, Ville Polojarvi, Antti Tukiainen, Jarno Reuna, Leo Peltomaa, Mircea Guina
Summary: This article discusses the progress in developing lattice-matched GaAs-based solar cells with a focus on expanding the spectral coverage range, by assessing the performance of a four-junction solar cell to explore possibilities for further efficiency improvements, and demonstrating the integration of materials like AlGaInP and GaInNAsSb to achieve higher efficiencies in solar cells.
PROGRESS IN PHOTOVOLTAICS
(2021)
Article
Chemistry, Physical
Piotr Tatarczak, Henryk Turski, Krzysztof P. Korona, Ewa Grzanka, Czeslaw Skierbiszewski, Andrzej Wysmolek
Summary: Detailed comparison of optical quality of GaN layers grown homoepitaxially on bulk Ga-polar and N-polar substrates by plasma-assisted molecular beam epitaxy was conducted. Layers grown on N-polar substrates showed one order of magnitude lower photo-luminescence intensity and decay time due to gallium-rich conditions, while nitrogen-rich growth conditions greatly improved the optical quality by suppressing formation of nitrogen vacancy-related point defects. Layers grown on N-polar substrates achieved linewidth below 1 meV and lifetime above 0.1 ns at He temperature.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Inorganic & Nuclear
Brandon D. Piercy, Jamie P. Wooding, Shawn A. Gregory, Mark D. Losego
Summary: The study demonstrates the use of in situ pulsed heating to promote epitaxial growth of ZnO thin films with high crystal quality and epitaxial characteristics. By controlling the temperature and cycle of heating pulses, the crystal structure and growth rate of the films can be affected.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Physical
C. Palade, A. M. Lepadatu, A. Slav, S. Lazanu, V. S. Teodorescu, T. Stoica, M. L. Ciurea
APPLIED SURFACE SCIENCE
(2018)
Article
Multidisciplinary Sciences
A-M Lepadatu, A. Slav, C. Palade, I Dascalescu, M. Enculescu, S. Iftimie, S. Lazanu, V. S. Teodorescul, M. L. Ciurea, T. Stoica
SCIENTIFIC REPORTS
(2018)
Article
Engineering, Electrical & Electronic
Roger Loo, Yosuke Shimura, Shinichi Ike, Anurag Vohra, Toma Stoica, Daniela Stange, Dan Buca, David Kohen, Joe Margetis, John Tolle
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2018)
Article
Physics, Applied
C. Palade, A. Slav, A. M. Lepadatu, A. V. Maraloiu, I. Dascalescu, S. Iftimie, S. Lazanu, M. L. Ciurea, T. Stoica
APPLIED PHYSICS LETTERS
(2018)
Article
Chemistry, Physical
M. T. Sultan, J. T. Gudmundsson, A. Manolescu, T. Stoica, M. L. Ciurea, H. G. Svavarsson
APPLIED SURFACE SCIENCE
(2019)
Article
Nanoscience & Nanotechnology
C. Palade, A. Slav, A. M. Lepadatu, I Stavarache, I Dascalescu, A. Maraloiu, C. Negrila, C. Logofatu, T. Stoica, V. S. Teodorescu, M. L. Ciurea, S. Lazanu
Article
Nanoscience & Nanotechnology
Ioana Dascalescu, Nicolae C. Zoita, Adrian Slav, Elena Matei, Sorina Iftimie, Florin Comanescu, Ana-Maria Lepadatu, Catalin Palade, Sorina Lazanu, Dan Buca, Valentin S. Teodorescu, Magdalena L. Ciurea, Mariana Braic, Toma Stoica
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Nanoscience & Nanotechnology
Adrian Slav, Ioana Dascalescu, Ana-Maria Lepadatu, Catalin Palade, Nicolae C. Zoita, Hermine Stroescu, Sorina Iftimie, Sorina Lazanu, Mariuca Gartner, Dan Buca, Valentin S. Teodorescu, Magdalena L. Ciurea, Mariana Braic, Toma Stoica
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Chemistry, Physical
Ionel Stavarache, Ovidiu Cojocaru, Valentin Adrian Maraloiu, Valentin Serban Teodorescu, Toma Stoica, Magdalena Lidia Ciurea
Summary: This study investigated Al2O3/Ge/Al2O3 trilayer memory structures deposited on p-Si substrates, revealing different effects of rapid thermal annealing (RTA) at various temperatures on the structure, morphology, and memory properties. The results showed changes in Ge diffusion, formation of Ge nanocrystals and mixed oxide nanoparticles at different annealing temperatures, leading to variations in the memory window size and charge loss behavior over time.
APPLIED SURFACE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Ovidiu Cojocaru, Ana-Maria Lepadatu, George Alexandru Nemnes, Toma Stoica, Magdalena Lidia Ciurea
Summary: A detailed study on the bandgap dependence of spherical Ge-rich GexSi1-x nanocrystals was conducted using atomistic density functional theory calculations. The results show a composition invariance of the bandgap diameter dependence, with the bandgap of NCs being well described by a power function for a certain diameter range. H-passivation of the NC surface helps accurately determine the NC bandgap by excluding surface states near the band edges.
SCIENTIFIC REPORTS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
A. M. Lepadatu, C. Palade, A. Slav, I Dascalescu, O. Cojocaru, S. Iftimie, V. S. Teodorescu, T. Stoica, M. L. Ciurea
CAS 2020 PROCEEDINGS: 2020 INTERNATIONAL SEMICONDUCTOR CONFERENCE
(2020)
Article
Chemistry, Physical
Ana-Maria Lepadatu, Catalin Palade, Adrian Slav, Ovidiu Cojocaru, Valentin-Adrian Maraloiu, Sorina Iftimie, Florin Comanescu, Adrian Dinescu, Valentin S. Teodorescu, Toma Stoica, Magdalena L. Ciurea
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Analytical
Catalin Palade, Ionel Stavarache, Toma Stoica, Magdalena Lidia Ciurea
Proceedings Paper
Engineering, Electrical & Electronic
I. Dascalescu, O. Cojocaru, I. Lalau, C. Palade, A. Slav, A. M. Lepadatu, S. Lazanu, T. Stoica, M. L. Ciurea
2019 INTERNATIONAL SEMICONDUCTOR CONFERENCE (CAS 2019), 42ND EDITION
(2019)
Article
Nanoscience & Nanotechnology
Adrian Slav, Catalin Palade, Constantin Logofatu, Ioana Dascalescu, Ana M. Lepadatu, Ionel Stavarache, Florin Comanescu, Sorina Iftimie, Stefan Antohe, Sorina Lazanu, Valentin S. Teodorescu, Dan Buca, Magdalena L. Ciurea, Mariana Braic, Toma Stoica
ACS APPLIED NANO MATERIALS
(2019)
