Article
Physics, Condensed Matter
I Gorczyca, G. Staszczak, G. Targowski, E. Grzanka, J. Smalc-Koziorowska, T. Suski, T. Kawamura, Y. Kangawa
Summary: The use of superlattices of InxGa1-xN/InyGa1-yN type allows for more precise tuning of emission energy and shifting light emission to lower energies. This approach can overcome the technological problem of low In incorporation in InGaN based heterostructures.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Crystallography
Polyxeni Chatzopoulou, Isaak G. Vasileiadis, Philomela Komninou, Vassilis Pontikis, Theodoros Karakostas, George P. Dimitrakopulos
Summary: The use of strained substrates can overcome indium incorporation limits without causing plastic relaxation in InGaN quantum wells, which is particularly important for short-period InGaN/GaN superlattices. Elastic strain in these heterostructures modifies their optoelectronic behavior. Density functional theory calculations were used to investigate the band-gap energy variation in short-period InGaN/GaN superlattices with one monolayer thick pseudomorphic quantum wells. Heterostructures with equibiaxially strained GaN barriers were compared to those with relaxed barriers. The study reveals a reduction of the band gap with lower indium contents, attributed to the influence of highly strained nitrogen sublattice. However, above mid-range indium compositions, the band gap increases with indium content due to the reduction of compressive strain in quantum wells caused by the tensile strain of barriers. Indium clustering induced by phase separation was considered as another modifier, but it was found to have no significant influence on the band gap. Overall, this study provides important insights into the behavior of band-gap energy in strained superlattices, optimizing the performance of optoelectronic devices based on InGaN/GaN heterostructures.
Article
Chemistry, Inorganic & Nuclear
Takayuki Suehiro, Masataka Tansho, Toru Ishigaki, Tadashi Shimizu
Summary: The study investigated the ZnGeN2-GaN solid-solution system in previously unexplored compositional regions, revealing the transitional properties caused by the introduction of Ga. The results showed that increasing Ga content led to gradual red shifts in the absorption and photoluminescence properties of the samples.
INORGANIC CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Xubo Zhu, Wanqi Jie, Yanqiu Lyu, Zhenyu Peng, Jinchun Wang, Yingjie He, Mo Li, Lixue Zhang, Zhenming Ji
Summary: Using the empirical sp(3)s* tight-binding method, the band edge energy and effective mass of type II superlattices on a (0 0 1) GaSb substrate at different temperatures were investigated. The band gap of InAs/GaSb superlattices and InAs/GaSb/AlSb/GaSb M-structure was fitted using empirical Varshni's equation. The effective mass as a function of temperature was calculated through the numerical second derivative of the band energy dispersion curve. Furthermore, a model of P-pi-M-N device structure of superlattices was established to describe the dependence of band structure on the working temperature.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Physical
Grzegorz Staszczak, Iza Gorczyca, Ewa Grzanka, Julita Smalc-Koziorowska, Grzegorz Targowski, Tadeusz Suski
Summary: To achieve red emission in nitride quantum structures, the low In incorporation in InGaN-based heterostructures needs to be addressed. By changing the superlattice parameters and the composition of the buffer structures, the light emission can be shifted to lower energies.
Article
Physics, Multidisciplinary
QuanSheng Wu, Jianpeng Liu, Yifei Guan, Oleg Yazyev
Summary: The study shows that different configurations of twisted double bilayer graphene exhibit distinct Landau level sequences in the Hofstadter butterfly spectra, reflecting the differences in valley Chern numbers of their flat bands. These differences can be explained by analyzing the distribution of orbital magnetization in momentum space.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Xubo Zhu, Wanqi Jie, Yanqiu Lyu, Zhenyu Peng, Xiancun Cao, Mo Li, Guansheng Yao, Lixue Zhang
Summary: When the operating temperature rapidly decreases from room temperature to 77 K, the band structure of InAs/GaSb superlattices device is affected by thermal strain. Two strain models of the device with and without substrate were designed and fabricated, with the thickness of silicon ROIC identified as the main factor affecting band structure. A model with Al2O3 substrate and silicon ROIC thickness below 500 µm was recommended for having less bandgap deviation and the measured PL spectrum and spectral response confirmed the simulation results.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Multidisciplinary Sciences
Ciaran Mullan, Sergey Slizovskiy, Jun Yin, Ziwei Wang, Qian Yang, Shuigang Xu, Yaping Yang, Benjamin A. A. Piot, Sheng Hu, Takashi Taniguchi, Kenji Watanabe, Kostya S. S. Novoselov, A. K. Geim, Vladimir I. I. Falko, Artem Mishchenko
Summary: Van der Waals assembly allows for the design of electronic states in 2D materials by superimposing a long-wavelength periodic potential. This twistronics approach has led to various new physics phenomena and can also be applied to tune electronic states in 3D crystals.
Article
Materials Science, Multidisciplinary
Michel Lannoo, P. Tim Prins, Zeger Hens, Daniel Vanmaekelbergh, Christophe Delerue
Summary: By studying the absorptance spectra of nanometer-thin layers of various semiconductors, researchers have found that the optical absorptance exhibits similar characteristics to graphene, with marked plateaus at integer values of pi alpha. This quantization of absorptance is universal in semiconductor quantum wells, as long as excitonic effects are weak, and is not specific to graphene. The physical origin of this universality is explained using analytical models, which show that the absorptance is ruled by pi alpha independent of the material characteristics.
Article
Chemistry, Physical
Ana-Maria Stratulat, Christian Tantardini, Maryam Azizi, Tariq Altalhi, Sergey V. Levchenko, Boris I. Yakobson
Summary: We propose the Zn2V(1-x)NbxN-3 alloy as a promising material for optoelectronic applications, specifically for light-emitting diodes (LEDs). Accurate electronic structure calculations using density-functional theory reveal a tunable band gap range suitable for developing bright LEDs as potential replacements for Ga(1-x)In(x)N systems. The effects of configurational disorder are considered, and the band gap's nonlinear behavior is evaluated for different concentration scenarios.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Qiming Chen, Ning Gong, Tanrui Zhu, Changyu Yang, Wenchao Peng, Yang Li, Fengbao Zhang, Xiaobin Fan
Summary: The study presents a surface phase engineering strategy to enhance the OER performance of transition metal nitrides, with the synthesized FeNi3-N catalyst showing excellent OER performance in alkaline media. The dual-phase nitrides induced by atom migration on the surface of the catalyst are favorable for decreasing the energy barrier, balancing the absorption and desorption of intermediates, and promoting the OER electrochemical performance.
Review
Materials Science, Multidisciplinary
Bin Tian, Derek Ho, Jiaqian Qin, Jinguang Hu, Zhangxing Chen, Damien Voiry, Qian Wang, Zhiyuan Zeng
Summary: Polymeric carbon nitrides (CN) have attracted increasing attention as star semiconductive materials due to their facile synthesis, non-toxicity, earthabundant, high physicochemical stability, and potential in various fields. This review systematically summarized the breakthroughs on the rational design and fabrication of CN framework from elements to monomers, and then to tectonic units via various strategies, as well as the general rules between CN framework structure and their performance in various applications.
PROGRESS IN MATERIALS SCIENCE
(2023)
Article
Physics, Multidisciplinary
Zhehao Ge, Sergey Slizovskiy, Frederic Joucken, Eberth A. Quezada, Takashi Taniguchi, Kenji Watanabe, Vladimir Fal'ko, Jairo Velasco
Summary: Trilayer graphene with Bernal stacking is found to have topological magnetic moments with a large and widely tunable valley g factor, which can be utilized for creating valleytronic devices. The experimental results match well with the theoretical modeling, demonstrating the potential of controlling TLG bands under perpendicular electric and magnetic fields.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Yasin Yekta, Hanif Hadipour, Seyed Akbar Jafari
Summary: The authors use ab initio calculations to understand the atomic origin of the tilt in the two-dimensional Dirac cone of 8Pmmn borophene and suggest atomic substitutions to vary the tilt. Borophene, a single layer of boron atoms, has many of the exotic properties of graphene.
COMMUNICATIONS PHYSICS
(2023)
Article
Multidisciplinary Sciences
Kate Reidy, Georgios Varnavides, Joachim Dahl Thomsen, Abinash Kumar, Thang Pham, Arthur M. Blackburn, Polina Anikeeva, Prineha Narang, James M. LeBeau, Frances M. Ross
Summary: Advanced scanning transmission electron microscopy techniques are used to image the atomic structure at the interface between 2D MoS2 and 3D Au nanoislands, revealing a moire superlattice and illustrating the potential for (opto-)electronic moire engineering at the 2D/3D interface.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Applied
Anna Kafar, Szymon Stanczyk, Szymon Grzanka, Katarzyna Pieniak, Tadeusz Suski, Piotr Perlin
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Piotr A. Drozdz, Krzysztof P. Korona, Marcin Sarzynski, Szymon Grzanka, Robert Czernecki, Tadeusz Suski
JOURNAL OF APPLIED PHYSICS
(2019)
Article
Physics, Applied
I. Gorczyca, K. Skrobas, N. E. Christensen, J. Sajkowski, M. Stachowicz, H. Teisseyre, A. Kozanecki
JOURNAL OF APPLIED PHYSICS
(2019)
Article
Physics, Condensed Matter
Takahiro Kawamura, Yuma Fujita, Yuya Hamaji, Toru Akiyama, Yoshihiro Kangawa, Izabela Gorczyca, Tadeusz Suski, Malgorzata Wierzbowska, Stanislaw Krukowski
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2020)
Article
Chemistry, Inorganic & Nuclear
Alexandra Filatova-Zalewska, Zenon Litwicki, Tadeusz Suski, Andrzej Jezowski
SOLID STATE SCIENCES
(2020)
Article
Multidisciplinary Sciences
Lucja Marona, Dario Schiavon, Michal Baranowski, Robert Kudrawiec, Iza Gorczyca, Anna Kafar, Piotr Perlin
SCIENTIFIC REPORTS
(2020)
Article
Optics
A. Kafar, R. Ishii, K. Gibasiewicz, Y. Matsuda, S. Stanczyk, D. Schiavon, S. Grzanka, M. Tano, A. Sakaki, T. Suski, P. Perlin, M. Funato, Y. Kawakami
Article
Optics
Krzysztof Gibasiewicz, Agata Bojarska-Cieslinska, Grzegorz Muziol, Czeslaw Skierbiszewski, Szymon Grzanka, Anna Kafar, Piotr Perlin, Stephen Najda, Tadeusz Suski
Article
Optics
Mikolaj Chlipala, Henryk Turski, Marcin Siekacz, Katarzyna Pieniak, Krzesimir Nowakowski-Szkudlarek, Tadeusz Suski, Czeslaw Skierbiszewski
Article
Optics
K. Pieniak, M. Chlipala, H. Turski, W. Trzeciakowski, G. Muziol, G. Staszczak, A. Kafar, I Makarowa, E. Grzanka, S. Grzanka, C. Skierbiszewski, T. Suski
Summary: This study investigates the impact of injected current on the screening of the built-in electric field in LEDs, revealing that in LEDs with narrow quantum wells, a large portion of built-in field remains even at high injection currents, while in LEDs with wide quantum wells, the electric field is fully screened even at the lowest currents.
Article
Optics
A. Kafar, A. Sakaki, R. Ishii, S. Stanczyk, K. Gibasiewicz, Y. Matsuda, D. Schiavon, S. Grzanka, T. Suski, P. Perlin, M. Funato, Y. Kawakami
Summary: The study demonstrates the modification of epitaxial laser-like or superluminescent diode-like structures by intentional changes in substrate misorientation, affecting the indium content in the quantum well and photoluminescence emission wavelength. Simulation results show that good light guiding properties should be preserved within the studied misorientation range.
PHOTONICS RESEARCH
(2021)
Proceedings Paper
Computer Science, Artificial Intelligence
S. P. Najda, P. Perlin, T. Suski, S. Stanczyk, M. Leszczynski, D. Schiavon, T. Slight, S. Gwyn, S. Watson, A. E. Kelly, M. Knapp, M. Haji
SPIE FUTURE SENSING TECHNOLOGIES (2020)
(2020)
Article
Materials Science, Multidisciplinary
I Gorczyca, M. Wierzbowska, I. D. Jarosz, J. Z. Domagala, A. Reszka, D. Le Si Dang, F. Donatini, N. E. Christensen, H. Teisseyre
Article
Materials Science, Multidisciplinary
G. Staszczak, W. Trzeciakowski, E. Monroy, A. Bercha, I. G. Muziol, C. Skierbiszewski, P. Perlin, T. Suski
Proceedings Paper
Optics
S. P. Najda, P. Perlin, T. Suski, L. Marona, S. Stanczyk, P. Wisniewski, S. Grzanka, D. Schiavon, M. Leszczynski
QUANTUM SENSING AND NANO ELECTRONICS AND PHOTONICS XVI
(2019)