Article
Physics, Applied
T. Auzelle, C. Sinito, J. Laehnemann, G. Gao, T. Flissikowski, A. Trampert, S. Fernandez-Garrido, O. Brandt
Summary: We compared the properties of GaN/(Al,Ga)N multiple quantum wells grown by PA MBE and found that different polarity samples are comparable in terms of their morphological and structural perfection. At room temperature, N-polar samples exhibit better performance.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Yu Fang, Xingzhi Wu, Junyi Yang, Jianping Wang, Quanying Wu, Yinglin Song
Summary: The impact of carbon defects on carrier trapping and recombination processes in high-quality GaN crystals was investigated using transient absorption spectroscopy, revealing that even at low defect concentrations, carbon in GaN significantly reduces the efficiency of optoelectronic devices.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Sonachand Adhikari, Olivier Lee Cheong Lem, Felipe Kremer, Kaushal Vora, Frank Brink, Mykhaylo Lysevych, Hark Hoe Tan, Chennupati Jagadish
Summary: The growth of nonpolar m-plane AlGaN on GaN nanowires is limited by the shadowing effect. It is difficult to achieve metal-polar AlGaN nanowires through selective area growth in MOCVD. Nonpolar m-plane GaN nanowires obtained via selective area growth provide an excellent platform for the growth of nonpolar AlGaN MQWs.
Article
Materials Science, Multidisciplinary
R. Aristegui, F. Chiaruttini, B. Jouault, P. Lefebvre, C. Brimont, T. Guillet, M. Vladimirova, S. Chenot, Y. Cordier, B. Damilano
Summary: This study found that excitons in wide GaN/(Al, Ga)N quantum wells are made spatially indirect by a built-in electric field. The density of excitons in traps can be controlled by an external electric bias. Negative bias deepens the trapping potential, while positive bias releases the excitons.
Article
Materials Science, Ceramics
Hyun Jeong, Heedae Kim, Mun Seok Jeong
Summary: The optical characteristics of nonplanar a-plane and c-plane InGaN/GaN MQWs were studied, and it was found that the a-plane MQWs have a higher integrated PL intensity and a more uniform distribution of PL intensity in two-dimensional space compared to the c-plane MQWs. These results indicate that nonpolar a-plane InGaN/GaN MQWs have superior optical performance compared to typical c-plane MQWs.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Applied
A. Minj, M. Zhao, B. Bakeroot, K. Paredis
Summary: The current state of dopant assessment for the optimization of III-nitride-based heterostructures relies heavily on quantitative chemical analysis techniques, however, limitations exist due to poor activation of Mg, presence of O impurities, and amphoteric nature of carbon impurities. Exploitation of nanosize metal-semiconductor junction formed between the metallic scanning probe microscopy probe and III-nitride surface shows promise for carrier determination, especially in regions of interest requiring nanometer resolution.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Joshua M. McMahon, Emmanouil Kioupakis, Stefan Schulz
Summary: We present an atomistic theoretical study of the competition between Auger and radiative recombination in c-plane (In,Ga)N/GaN quantum wells. The results show that the total Auger recombination rate exhibits a weak temperature dependence, and the hole-hole-electron Auger rate dominates the total rate for different In contents. Our studies provide further insight into the origin of the thermal droop in (In,Ga)N-based light-emitting diodes, suggesting that the competition between radiative and nonradiative recombination is not the driving force behind this droop effect.
Article
Chemistry, Physical
Xianshao Zou, Jianqi Dong, Kang Zhang, Weihua Lin, Meiyuan Guo, Wei Zhang, Xingfu Wang
Summary: Piezotronic effects promote charge separation of excitons and slow down the recombination rate of free carriers in InGaN/GaN multiple quantum wells microwire (MQW-MW). This phenomenon is supported by three independent experiments, providing guidance for the application of piezotronics in optoelectronic devices based on MQW-MW.
Article
Engineering, Electrical & Electronic
Masaya Chizaki, Kensuke Oki, Yoshihiro Ishitani
Summary: This study investigates the relationship between exciton radiative lifetime and crystal quality. By using a calculation model, the authors find that temperature affects the exciton radiative lifetime, and this effect is related to crystal quality.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Physics, Applied
Artem Bercha, Grzegorz Muziol, Mikolaj Chlipala, Witold Trzeciakowski
Summary: Time-resolved photoluminescence measurements were conducted on (In, Ga)N/GaN quantum well light-emitting diodes (LEDs). It was found that charge carriers in ground states can still be detected even after optical excitation. These charge carriers, known as dark charge, do not recombine radiatively but screen the electric field in the well. The intensity of optical transitions is sensitive to the population of dark charge. The dark charge can be depleted by applying negative voltage pulses, and this regeneration effect allows estimation of the electric field in the well.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
Huan-Ting Shen, Claude Weisbuch, James S. Speck, Yuh-Renn Wu
Summary: The lateral diffusion length of carriers in nitride-based green, blue, and UVC QWs is limited by potential fluctuations and recombination rates, which are influenced by spontaneous and piezoelectric fields in the QWs, as well as carrier screening of internal electric fields. The study highlights the impact of alloy disorders on LED efficiency and carrier diffusion length.
PHYSICAL REVIEW APPLIED
(2021)
Article
Chemistry, Multidisciplinary
Gunnar Kusch, Ella J. Comish, Kagiso Loeto, Simon Hammersley, Menno J. Kappers, Phil Dawson, Rachel A. Oliver, Fabien C-P Massabuau
Summary: Time-resolved cathodoluminescence offers new possibilities for studying carrier recombination at the nanoscale, providing insights into the emission properties of defects in semiconductor nanostructures. The study found a close relationship between the emission properties of trench defects and the depth of related basal plane stacking faults within quantum well stacks, supporting the hypothesis that strain relaxation within the trench promotes efficient radiative recombination in the presence of increased indium content. This highlights the versatility and power of cathodoluminescence as a tool for investigating defects in semiconductors.
Article
Physics, Applied
Julian Veletas, Thilo Hepp, Florian Dobener, Kerstin Volz, Sangam Chatterjee
Summary: Efficient semiconductor lasers on GaAs substrates operating at 1.55 μm and beyond pose a technological challenge, with epitaxial heterostructures featuring type-II band alignment being considered as a potential solution. The symmetry of the layer arrangement in such heterostructures significantly influences charge-carrier recombination, with disorder in certain layers having more prominent effects in asymmetric configurations. Temperature dependence of emission energy is mainly influenced by the Ga(N,As)-electron layers, while full width at half maximum and excitation dependence of emission energy are dominated by the Ga(As,Bi)-hole layers.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Condensed Matter
Junsen Mo, Qilin Hua, Wei Sha, Mingyue Yao, Jiangwen Wang, Lingyu Wan, Junyi Zhai, Tao Lin, Weiguo Hu
Summary: The study looks at carrier dynamics in flexible III-nitride optoelectronic devices under external stress regulation, finding a non-monotonic relationship between photoluminescence intensity and carrier lifetime with increasing stress, leading to a maximum PL enhancement of around 19%. This reveals how internal stress affects optoelectronic performance in compensating for the built-in piezoelectric field in InGaN wells.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Chemistry, Physical
Dominika Majchrzak, Milosz Grodzicki, Karolina Moszak, Ewelina Zdanowicz, Jaroslaw Serafinczuk, Damian Pucicki, Robert Kudrawiec, Detlef Hommel
Summary: Analysis of AlN epitaxial layers grown by molecular beam epitaxy (MBE) reveals the presence of Al-Al and N-N bonds, as well as a rough 3D-like structure. By employing low flux Al deposition in pulsed mode at the end of MBE growth, significant improvement in surface quality is achieved, leading to enhanced optical properties in Al0.85Ga0.15N/GaN multiple quantum wells (MQWs) growth. The introduction of pulsed low flux Al deposition shows a clear advantage in relative intensity between QW emission and low energy emission during photoluminescence studies.
SURFACES AND INTERFACES
(2021)
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)
Article
Chemistry, Physical
Jacek Piechota, Stanislaw Krukowski, Petro Sadovyi, Bohdan Sadovyi, Sylwester Porowski, Izabella Grzegory
Summary: The study investigated the dissolution of molecular nitrogen in liquid gallium and iron through ab initio calculations and experiments, revealing fundamental differences in N bonding between the two solvents. It was found that the nitrogen solubility in iron is much higher than in gallium, indicating that liquid iron may be a prospective solvent for gallium nitride crystallization from metallic solutions.
Article
Chemistry, Multidisciplinary
Thomas F. K. Weatherley, Wei Liu, Vitaly Osokin, Duncan T. L. Alexander, Robert A. Taylor, Jean-Francois Carlin, Raphael Butte, Nicolas Grandjean
Summary: This study demonstrates the successful spatial resolution and analysis of nonradiative point defects in InGaN/GaN quantum wells using high-resolution cathodoluminescence. The different types of point defects were identified by contrasting behaviors and their densities were measured from 10^14 cm^-3 to as high as 10^16 cm^-3. The results show the interplay between point defects and carrier dynamics, highlighting the impact of point defects on carrier diffusion lengths and nonradiative behaviors.
Article
Multidisciplinary Sciences
D. M. Di Paola, P. M. Walker, R. P. A. Emmanuele, A. V. Yulin, J. Ciers, Z. Zaidi, J. -F. Carlin, N. Grandjean, I. Shelykh, M. S. Skolnick, R. Butte, D. N. Krizhanovskii
Summary: The authors demonstrate the giant nonlinearity of UV hybrid light-matter states (exciton-polaritons) in an AlInGaN waveguide, which can achieve ultrafast spectral broadening and offer promise for the development of a new generation of integrated UV nonlinear light sources.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Ashfaq Ahmad, Pawel Strak, Kamil Koronski, Pawel Kempisty, Konrad Sakowski, Jacek Piechota, Izabella Grzegory, Aleksandra Wierzbicka, Serhii Kryvyi, Eva Monroy, Agata Kaminska, Stanislaw Krukowski
Summary: This study uses ab initio calculations to determine the polarization difference in III-nitride compounds, showing varying polarization differences between different nitrides. In multi-quantum wells, electric fields are generated by well-barrier polarization difference, and the theoretical results are in good agreement with experimental measurements.
Article
Chemistry, Physical
Pawel Strak, Konrad Sakowski, Jacek Piechota, Ashfaq Ahmad, Izabella Grzegory, Yoshihiro Kangawa, Stanislaw Krukowski
Summary: The adsorption of atomic and molecular nitrogen on the AlN(000-1) surface was investigated using ab initio calculations and thermodynamic analysis. Different adsorption behaviors and energy changes of nitrogen were observed at various aluminum coverage levels, providing insights into the mechanisms of nitrogen adsorption on the AlN surface.
Review
Optics
Johann Stachurski, Sebastian Tamariz, Gordon Callsen, Raphael Butte, Nicolas Grandjean
Summary: This study reports on the emission properties evolution of GaN/AlN quantum dots (QDs) at different temperatures. By studying the photoluminescence of a single QD, the optimum single photon purity was measured. Temperature dependent time-resolved photoluminescence measurements on a QD ensemble revealed the complexity and temperature insensitivity of exciton recombination dynamics in this nanostructure.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Optics
Anat Siddharth, Thomas Wunderer, Grigory Lihachev, Andrey S. Voloshin, Camille Haller, Rui Ning Wang, Mark Teepe, Zhihong Yang, Junqiu Liu, Johann Riemensberger, Nicolas Grandjean, Noble Johnson, Tobias J. Kippenberg
Summary: Low phase noise lasers based on III-V semiconductors and silicon photonics have been widely used in the near-infrared spectral regime. Recent advancements in low-loss silicon nitride-based photonic integrated resonators have surpassed external diode and fiber lasers in terms of phase noise and frequency agility in the 1550 nm-telecommunication window. In this study, we demonstrate a hybrid integrated laser composed of a gallium nitride-based laser diode and a silicon nitride photonic chip-based microresonator operating at ultra-low wavelengths down to 410 nm in the near-ultraviolet wavelength region, which is suitable for atomic transitions addressing in applications such as atomic clocks, quantum computing, or underwater LiDAR. By self-injection locking of the Fabry-Perot diode laser to a high-Q photonic integrated microresonator, we achieve more than 100x reduction in optical phase noise at 461 nm, limited by the device quality factor and back-reflection.
Article
Physics, Applied
Ashfaq Ahmad, Pawel Strak, Pawel Kempisty, Konrad Sakowski, Jacek Piechota, Yoshihiro Kangawa, Izabella Grzegory, Michal Leszczynski, Zbigniew R. Zytkiewicz, Grzegorz Muziol, Eva Monroy, Agata Kaminska, Stanislaw Krukowski
Summary: This work investigates the emergence of polarization doping in AlxGa1-xN layers with graded composition from a theoretical viewpoint. It shows that bulk electric charge density emerges in the graded concentration region and obtains the relation between the polarization bulk charge density and the concentration gradient. The study also demonstrates that a mobile charge appears due to the increase of the distance between opposite polarization-induced charges.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Tomasz Stefaniuk, Jan Suffczynski, Malgorzata Wierzbowska, Jaroslaw Z. Domagala, Jaroslaw Kisielewski, Andrzej Klos, Alexander Korneluk, Henryk Teisseyre
Summary: In this study, the optical, electronic, and structural properties of ScAlMgO4 are investigated using ScAlMgO4 single crystals grown by the Czochralski method. The results show that ScAlMgO4 has excellent refractive indices and lattice constants, making it a suitable material for low-threshold, deep-UV lasing devices.
Proceedings Paper
Optics
Nicola Roccato, Francesco Piva, Carlo De Santi, Riccardo Brescancin, Kalparupa Mukherjee, Matteo Buffolo, Camille Haller, Jean-Francois Carlin, Nicolas Grandjean, Marco Vallone, Alberto Tibaldi, Francesco Bertazzi, Michele Goano, Giovanni Verzellesi, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: This paper analyzes the impact of defects on the electrical characteristics of InGaN light-emitting diodes (LEDs) and determines the energy levels and concentrations of these defects through simulation and measurement. The results show that these defects have a significant influence on the current-voltage characteristics of LEDs, especially in the sub turn-on region.
GALLIUM NITRIDE MATERIALS AND DEVICES XVII
(2022)
Proceedings Paper
Engineering, Manufacturing
Matteo Buffolo, Nicola Roccato, Francesco Piva, Carlo De Santi, Riccardo Brescancin, Claudia Casu, Alessandro Caria, Kalparupa Mukherjee, Camille Haller, Jean Francois Carlin, Nicolas Grandjean, Marco Vallone, Alberto Tibaldi, Francesco Bertazzi, Michele Goano, Giovanni Verzellesi, Mauro Mosca, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: This presentation discusses the experimental characterization of defect properties and the modeling of their impact on the electro-optical characteristics of III-N light-emitting diodes (LEDs).
LIGHT-EMITTING DEVICES, MATERIALS, AND APPLICATIONS XXVI
(2022)
Article
Materials Science, Multidisciplinary
R. Aristegui, F. Chiaruttini, B. Jouault, P. Lefebvre, C. Brimont, T. Guillet, M. Vladimirova, S. Chenot, Y. Cordier, B. Damilano
Summary: This study found that excitons in wide GaN/(Al, Ga)N quantum wells are made spatially indirect by a built-in electric field. The density of excitons in traps can be controlled by an external electric bias. Negative bias deepens the trapping potential, while positive bias releases the excitons.
Article
Materials Science, Multidisciplinary
F. Chiaruttini, T. Guillet, C. Brimont, D. Scalbert, S. Cronenberger, B. Jouault, P. Lefebvre, B. Damilano, M. Vladimirova
Summary: Using spatially resolved magnetophotoluminescence spectroscopy, we demonstrated the Mott transition from a dipolar excitonic to an electron-hole plasma state in a wide GaN/(Al,Ga)N quantum well at T = 7 K. The carrier density at the Mott transition was estimated to be approximately 2 x 10^(11) cm^(-2), and the role of excitonic correlations in this process was addressed. Unlike GaAs/(Al,Ga)As systems, where dipolar magnetoexciton transport is strongly quenched by the magnetic field, in GaN/(Al,Ga)N systems, the transport is preserved up to 9 T due to the band parameters.
