Article
Physics, Applied
D. N. Lobanov, K. E. Kudryavtsev, M. Kalinnikov, L. Krasilnikova, P. A. Yunin, E. Skorokhodov, M. Shaleev, A. Novikov, B. A. Andreev, Z. F. Krasilnik
Summary: This study reports on stimulated emission (SE) in the near-infrared range from planar InGaN epitaxial layers grown on sapphire substrates. The research found that at temperatures around 190-210K, nonradiative recombination processes dominate the temperature quenching of stimulated emission. Different defect centers play a role in providing free electrons for both InN and InGaN layers, affecting the Shockley-Read-Hall (SRH) recombination rate at high temperatures.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Karol Olszewski, Marta Sobanska, Vladimir G. Dubrovskii, Egor D. Leshchenko, Aleksandra Wierzbicka, Zbigniew R. Zytkiewicz
Summary: This study focused on the growth of GaN nanowires on Si(111) substrates using plasma-assisted molecular beam epitaxy, specifically investigating the orientation and growth rate of the nanowires. The researchers found that vertically aligned nanowires grew faster and produced more regular ensembles compared to inclined nanowires. These densely packed ensembles of vertically aligned GaN nanowires on ZrN/Si(111) surfaces are highly relevant for device applications.
Article
Multidisciplinary Sciences
Janusz Sadowski, Anna Kaleta, Serhii Kryvyi, Dorota Janaszko, Boguslawa Kurowska, Marta Bilska, Tomasz Wojciechowski, Jaroslaw Z. Domagala, Ana M. Sanchez, Slawomir Kret
Summary: The incorporation of Bi into GaAs-(Ga,Al)As-Ga(As,Bi) core-shell nanowires grown by molecular beam epitaxy is studied. Bi-doped shells are smooth at low Bi fluxes, while higher Bi fluxes lead to Bi droplet segregation on the nanowire sidewalls, acting as catalysts for the growth of branches.
SCIENTIFIC REPORTS
(2022)
Review
Chemistry, Multidisciplinary
Abdul Kareem K. Soopy, Zhaonan Li, Tianyi Tang, Jiaqian Sun, Bo Xu, Chao Zhao, Adel Najar
Summary: The review summarizes recent advancements in nitride nanostructures and their applications, including synthesis, growth, and application of nitride materials. The discussion focuses on the growth of nitride materials on various substrates and the recent development of In(Ga)N nanostructure applications. The review also addresses the challenges and future directions in the field.
Article
Engineering, Electrical & Electronic
Oleg A. Koshelev, Dmitrii Nechaev, Pavel N. Brunkov, Sergey Ivanov, Valentin N. Jmerik
Summary: The stress evolution in AlN templates was studied using different growth modes and conditions. Standard PA MBE growth led to high tensile stress, while NLs grown using MEE demonstrated a transition from compressive stress to stress-free growth. Further growth on MEE-NLs at various Al/N-2* ratios revealed a variety of stress evolution processes.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Applied
I. Ahmed, S. De Gendt, C. Merckling
Summary: The BaBiO3 perovskite oxide is an interesting material system that exhibits superconductivity when p-doped and predicted topological insulation when n-doped. High-quality single crystalline BaBiO3 films are grown on Si(001) substrates using molecular beam epitaxy, with the growth window established by systematically varying growth parameters.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
A. Adhikari, A. Lysak, A. Wierzbicka, P. Sybilski, A. Reszka, B. S. Witkowski, E. Przezdziecka
Summary: In this study, the growth of CdO alloy using plasma-assisted molecular beam epitaxy method was investigated. The CdO alloy showed great potential for optoelectronic device fabrication. Structural and morphological analysis were conducted using X-ray diffraction and Atomic Force Microscopy techniques, while composition analysis was done by Energy-dispersive X-ray spectroscopy. The optical properties of thin films were studied using UV-Vis spectroscopy, and it was found that the bandgap of the films is affected by the incorporation of Mg2+ ions.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
T. Dursap, M. Vettori, C. Botella, P. Regreny, N. Blanchard, M. Gendry, N. Chauvin, M. Bugnet, A. Danescu, J. Penuelas
Summary: This article presents a method to select and maintain the hexagonal wurtzite crystal phase in III-V semiconductor nanowires through molecular beam epitaxy, and successfully achieves the controlled growth of pure WZ phase by adjusting the V/III flux ratio. The potential benefits for electronics and opto-electronics applications are indicated by this successful controlled growth of WZ GaAs.
Article
Physics, Multidisciplinary
Xiang-Peng Zhou, Hai-Bing Qiu, Wen-Xian Yang, Shu-Long Lu, Xue Zhang, Shan Jin, Xue-Fei Li, Li-Feng Bian, Hua Qin
Summary: AlN/GaN resonant tunneling diodes (RTDs) grown on freestanding GaN substrates exhibit room temperature negative differential resistance (NDR) and two resonance peaks, with lower dislocation densities, flatter surface morphology, and steeper heterogeneous interfaces being key factors for achieving NDR.
Article
Materials Science, Multidisciplinary
A. Adhikari, A. Wierzbicka, Z. Adamus, A. Lysak, P. Sybilski, D. Jarosz, E. Przezdziecka
Summary: This work investigates a series of CdO layers grown on the m-plane sapphire substrate using the plasma-assisted molecular beam epitaxy technique. The relation between Cd and O2 parameters during growth influences the stoichiometry and affects the morphological, optical, and electrical properties of the layers. Various characterization techniques were employed to study the surface morphology, structural properties, optical bandgap, and electrical parameters of the CdO layers.
Article
Physics, Applied
Ding Wang, Shubham Mondal, Jiangnan Liu, Mingtao Hu, Ping Wang, Samuel Yang, Danhao Wang, Yixin Xiao, Yuanpeng Wu, Tao Ma, Zetian Mi
Summary: We demonstrate ferroelectric switching in yttrium-doped nitride semiconductors. Yttrium 0.07Al0.93N films were grown on GaN/sapphire templates and exhibited a coercive field of 6 MV/cm and a switchable polarization of 130 mu C/cm(2). Ferroelectric switching was confirmed through capacitance-voltage loops and polarity-sensitive wet etching. This study expands the family of nitride ferroelectrics and opens up possibilities for applications in III-nitride based devices.
APPLIED PHYSICS LETTERS
(2023)
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
Chemistry, Multidisciplinary
Rahmat Hadi Saputro, Ryo Matsumura, Naoki Fukata
Summary: This study reveals the mechanism of dopant redistribution in Sb-doped Ge epitaxial films grown by molecular beam epitaxy, providing insights into the behavior of substituted Sb atoms in forming n-type Ge films. The understanding of these processes opens up possibilities for achieving n(+)-Ge thin films for Ge-based devices with improved electrical properties.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Gustavo A. Alvarez, Joseph Casamento, Len van Deurzen, Md Irfan Khan, Kamruzzaman Khan, Eugene Jeong, Elaheh Ahmadi, Huili Grace Xing, Debdeep Jena, Zhiting Tian
Summary: Aluminum scandium nitride (AlScN) is gaining attention for its larger piezoelectric response compared to AlN, but alloying Sc with AlN reduces thermal conductivity. Self-heating limits power handling in AlScN devices, and we compared thermal conductivity of AlScN grown on different substrates.
MATERIALS RESEARCH LETTERS
(2023)
Article
Physics, Applied
Ping Wang, Ding Wang, Nguyen M. Vu, Tony Chiang, John T. Heron, Zetian Mi
Summary: Ferroelectricity has been successfully demonstrated in ScxAl1-xN epitaxial films grown on GaN templates by molecular beam epitaxy, showing distinct polarization switching and excellent properties, such as a high coercive field and long polarization retention time. This achievement opens up possibilities for integrating high-performance ferroelectric functionality into established semiconductor platforms for various electronic and photonic device applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Mustafa Aydin, Selman Mutlu, Ayse Erol, Janne Puustinen, Joonas Hilska, Mircea Guina, Omer Donmez
Summary: The drift velocity of electrons in an n-type modulation-doped GaAs0.96Bi0.04/Al0.15Ga0.85As quantum well structure was investigated. The results showed that the drift velocity increased linearly and reached saturation at low electric fields. The electron drift mobility was determined to be 2265 cm(2) Vs(-1) in the linear regime. The drift velocity saturated at approximately 6.1 x 10(6) cm s(-1) in the electric field range of 2.7-3.4 kV cm(-1). This saturation was attributed to the transfer of electrons from the QW layer to the barrier layer and L-valley, resulting in electron cooling via phonon scattering in the sample.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Biochemical Research Methods
Gianni Nteroli, Giulia Messa, Manoj K. Dasa, Antti Penttinen, Antti Harkonen, Mircea Guina, Adrian Gh. Podoleanu, Stella Koutsikou, Adrian Bradu
Summary: This study exploits the advantage of picosecond duration pulse laser to enhance the axial resolution of the optoacoustic microscopy instrument. Experimental results demonstrate a 50% improvement in axial resolution using excitation pulses of only 85 ps. The study also presents high-quality optoacoustic images of the brain of Xenopus laevis tadpole.
JOURNAL OF BIOMEDICAL OPTICS
(2022)
Article
Optics
S. C. Burd, J. -P. Penttinen, P. -Y. Hou, H. M. Knaack, S. Ranta, M. Maki, E. Kantola, M. Guina, D. H. Slichter, D. Leibfried, A. C. Wilson
Summary: This article presents two systems based on vertical-external-cavity surface-emitting lasers (VECSELs) that can generate ultraviolet laser light at 235 and 313 nm wavelengths, suitable for quantum information processing with trapped beryllium ions. Each system includes a compact, single-frequency, continuous-wave VECSEL that produces high-power near-infrared light and can be tuned over tens of nanometers. One system produces 2.4 W of power at 940 nm, which is converted to 54 mW of 235 nm light for photoionization of neutral beryllium atoms. The other system uses a gain mirror based on GaInNAs/GaAs quantum wells, extending the wavelength above 1200 nm with manageable strain in the GaAs lattice, and generates 1.6 W at 1252 nm, which is converted to 41 mW of 313 nm light for laser cooling of trapped 9Be+ ions and quantum state preparation and detection. The 313 nm system is also suitable for implementing high-fidelity quantum gates.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Omer Donmez, Mustafa Aydin, Selman Mutlu, Janne Puustinen, Joonas Hilska, Mircea Guina, Ayse Erol
Summary: We present experimental and analytical results on hot electron transport in as-grown and annealed n-type modulation-doped Al0.15Ga0.85As/GaAs0.96Bi0.4 quantum well structures. The drift mobility and velocity of the annealed sample are lower due to the increased 2D electron density caused by annealing. Hot electron transport occurs in parallel mode, and inter-valley transfer dominates at higher electric fields.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Optics
Nouman Zia, Samu-pekka Ojanen, Jukka Viheriala, Eero Koivusalo, Joonas Hilska, Heidi Tuorila, Mircea Guina
Summary: This paper presents a hybrid laser that combines GaSb-based semiconductor gain chips with Si3N4 photonic integrated circuits. The low-loss features of Si3N4 waveguides are utilized to integrate a tunable Si3N4 Vernier mirror. The laser exhibits a maximum output power of 15 mW and a tuning range of about 90 nm at room temperature. The low-loss performance of various Si3N4 building blocks for photonic integrated circuits is also confirmed.
Article
Energy & Fuels
Andrea Scaccabarozzi, Stefano Vichi, Sergio Bietti, Federico Cesura, Timo Aho, Mircea Guina, Federica Cappelluti, Maurizio Acciarri, Stefano Sanguinetti
Summary: We investigate the impact of quantum dot aspect ratio on the sub-gap absorption properties of GaAs/AlGaAs quantum dot intermediate band solar cells. Using droplet epitaxy, we grow AlGaAs solar cells with GaAs quantum dots, which allows for strain-free nanostructures with lattice matched materials. By varying the dot aspect ratio, we can tune the energy levels of the intermediate band, thereby altering the sub-gap absorption spectrum and charge carrier extraction. The tradeoff between thermal and optical extraction is crucial for the proper functioning of the intermediate band solar cells, with the photonic extraction mechanism from the quantum dots becoming dominant at room temperature.
PROGRESS IN PHOTOVOLTAICS
(2023)
Article
Energy & Fuels
Riku Isoaho, Antti Tukiainen, Juuso Puutio, Arttu Hietalahti, Jarno Reuna, Antti Fihlman, Elina Anttola, Miika Keranen, Arto Aho, Mircea Guina
Summary: This study reports a comprehensive optimization process for GaInNAsSb solar cells grown by molecular beam epitaxy. The results show that the quantum efficiency and current generation of narrow gap materials can be significantly improved by increasing the growth temperature and reducing the As/III beam equivalent pressure ratio. It is also found that increasing the Sb flux can improve the material quality and inhibit phase separation.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Engineering, Electrical & Electronic
Philipp Tatar-Mathes, Hoy-My Phung, Aaron Rogers, Patrik Rajala, Sanna Rant, Mircea Guina, Hermann Kahle
Summary: This study presents the operation of a semiconductor membrane external-cavity surface-emitting laser (MECSEL) using a gain membrane with a non-resonant cavity design. The MECSEL delivers watt-level output power, comparable to state-of-the-art results. The research shows that the design criteria for the MECSEL gain region can be relaxed compared to designs using distributed Bragg reflectors, minimizing the impact of defective Fabry-Perot micro-cavity effects.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Optics
Samu-Pekka Ojanen, Jukka Viheriala, Nouman Zia, Eero Koivusalo, Joonas Hilska, Heidi Tuorila, Mircea Guina
Summary: Photonic integrated circuits fabricated using a Si3N4 waveguide platform exhibit low losses in a wide wavelength region. A high-performance integrated laser with broad wavelength tunability near a 2.6 μm wavelength region is demonstrated, based on a Si3N4 photonic integrated circuit incorporating a tunable reflector and a AlGaInAsSb/GaSb quantum-well gain element. The platform also supports low propagation loss up to 3.5 μm.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
D. Mitten, M. Hart, S. H. Warner, J. -P. Penttinen, M. Guina, Y. Kaneda
Summary: A vertical external cavity surface emitting laser (VECSEL) has been developed for a sodium guide star application. Stable single frequency operation with 21 W of output power near 1178 nm with multiple gain elements while lasing in the TEM00 mode has been achieved. This is the first demonstration of a high power single frequency VECSEL using a twisted-mode configuration and multiple gain mirrors located at the cavity folds.
Article
Physics, Applied
Y. Q. Huang, V Polojarvi, A. Aho, R. Isoaho, T. Hakkarainen, M. Guina, I. A. Buyanova, W. M. Chen
Summary: This study demonstrates the existence of nonlinear spin response in nonmagnetic materials and showcases it in a (Ga, N)As-InAs quantum dot coupled all-semiconductor nanostructure. The observed spin nonlinearity can be conveniently tuned with an external magnetic field and potentially operates at a speed exceeding 1 GHz.
PHYSICAL REVIEW APPLIED
(2023)
Article
Optics
Samu-Pekka Ojanen, Jukka Viheriala, Nouman Zia, Eero Koivusalo, Joonas Hilska, Heidi Tuorila, Mircea Guina
Summary: A discrete, tunable photonic integrated laser is demonstrated for multiwavelength spectroscopy. The laser combines a reflective semiconductor optical amplifier with a photonic integrated circuit, allowing for switching between three distinct emission wavelengths. The design simplifies the tuning mechanism compared to other hybrid lasers.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Tristan Smolka, Michal Rygala, Joonas Hilska, Janne Puustinen, Eero Koivusalo, Mircea Guina, Marcin Motyka
Summary: The optical properties of GaSbBi layers grown on GaSb (100) substrates with different bismuth contents were investigated. The band gaps of the materials were determined using Fourier-transform photoluminescence spectra, revealing the presence of localized states connected to bismuth clustering. Time-resolved photoluminescence measurements based on single-photon counting were used to determine the characteristic photoluminescence decay time constants, which showed an increase with increasing bismuth content and clustering effects.
Article
Energy & Fuels
Janne Puustinen, Joonas Hilska, Arto Aho, Esperanza Luna, Antti Fihlman, Mircea Guina
Summary: The development of low bandgap GaAsNBi solar cells grown using MBE is reported, and the As/Ga flux ratio is found to play an important role in controlling the solar cell performance.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2024)
Proceedings Paper
Nanoscience & Nanotechnology
Jukka Viheriala, Topi Uusitalo, Heikki Virtanen, Behzad Namvar, Patrik Rajala, Sanna Ranta, Teemu Hakkarainen, Antti Tukiainen, Guilhem Almuneau, Mircea Guina
Summary: This paper presents the development of vertical cavity surface emitting lasers (VCSELs) operating at 4.2K for energy efficient optical links between cryogenic systems and room-temperature data storage systems. The design considerations, material models, and validation of required electro-optical-thermal models are discussed. Successful operation at mA-level injection is demonstrated.
2023 IEEE PHOTONICS SOCIETY SUMMER TOPICALS MEETING SERIES, SUM
(2023)
