Review
Optics
Tatsushi Hamaguchi
Summary: In this paper, we discuss the evolution of gallium nitride-based (GaN-based) VCSELs with curved mirrors. The discussion covers the fundamentals of VCSELs and GaN-based materials, the principle and history of curved-mirror cavities, and the latest research on applying this structure to GaN-based materials for VCSELs. The aim is to help readers understand the working principles and excellent characteristics of VCSELs with this cavity, such as efficiency, life, and stabilized mode behavior. The challenges and prospects of these devices are also discussed, along with their potential applications.
Article
Optics
Xingfei Zhang, Zhicong Li, Yiyun Zhang, Xuedong Wang, Xiaoyan Yi, Guohong Wang, Jinmin Li
Summary: Heterogeneous integration of nitrides on Si (100) has been achieved by transferring GaN epitaxial layer onto Si (100) using wafer bonding, laser lift-off, and chemical mechanical polishing (CMP) processes. The transferred GaN epilayer has reduced surface roughness and mitigated residual stress. Arrays of microcavities with diverse geometrics and sizes have been fabricated, allowing optically-pumped green lasing. Electrically-injected microdisks with low leakage current and reduced thermal effects have also been successfully fabricated.
Article
Chemistry, Physical
Bohayra Mortazavi, Fazel Shojaei, Alexander V. Shapeev, Xiaoying Zhuang
Summary: Carbon nitride nanoporous lattices, especially C6N7-based monolayers, exhibit stable and strong semiconductor properties with notable absorption of ultraviolet light. The combination of density functional theory (DFT) and machine learning interatomic potentials (MLIPs) provides insights into their energetic stability, electronic properties, mechanical response, and optical characteristics. The study confirms the robustness and efficiency of MLIPs in exploring complex phononic and mechanical/failure responses of low-symmetry and highly-porous conductive frameworks.
Article
Chemistry, Multidisciplinary
Dapeng Zhang, Baofeng Li, Xinlong Mao, Zitong Fan, Zhe Yang, Min Wei, Ailing Zhang, Jin Feng, Siwei Bi
Summary: This study investigates the effect of alkali solution on the electronic structure of H2O/g-C3N4 and the dynamic process of water splitting. It is found that alkali can promote hydrogen production in g-C3N4 by accelerating the decomposition of H2O into H+. The alkali also reduces the free energy for H2O splitting and changes the position of the rate-determining step, making it easier for H to capture excited electrons and form H2.
NEW JOURNAL OF CHEMISTRY
(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.
Review
Chemistry, Multidisciplinary
Lixia Zhao, Chang Liu, Kaiyou Wang
Summary: This review discusses the recent progress in improving the performance of III-N semiconductors by integrating them with plasmonics and/or micro resonators, and provides a promising outlook for highly-integrated, high speed, and efficient GaN-based optoelectronic devices in the future.
Article
Engineering, Electrical & Electronic
Mehdi Jahed, Alexander Caut, Jeroen Goyvaerts, Marc Rensing, Magnus Karlsson, Anders Larsson, Gunther Roelkens, Roel Baets, Peter O'Brien
Summary: This study investigates the angled flip-chip integration of a singlemode 850 nm VCSEL on a silicon nitride PIC. The conditions for high coupling efficiency and low optical feedback are examined using numerical simulations. Experimental results show that increasing the angle decreases the coupling efficiency and optical feedback, and co-directional coupling introduces first-order diffraction loss and further reduces the coupling efficiency.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Christopher M. Matthews, Zachary Engel, Keisuke Motoki, W. Alan Doolittle
Summary: The phase separation of indium-bearing III-nitrides is difficult to control, while for aluminum gallium nitride, it can be used to synthesize coherent superlattice structures with potential applications. This study proposes that phase separation in III-nitride alloys can be attributed to multiple surface-driven mechanisms, and a self-consistent model has been developed to investigate the evolution of surface adlayers and the formation of self-assembled superlattices in AlGaN. The combination of preferential cation incorporation and vertical cation segregation can explain the experimentally observed composition profiles.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Weiguo Xu, Qiuya Zhang, Xudong Kang, Hongli Guo, Jiabao Song, Liping Wang
Summary: In this study, a boron nitride modified CuWO4 composite photocatalytic material was prepared for the first time and its ability to degrade tetracycline was evaluated. The results showed that the introduction of boron nitride facilitated the separation of photogenerated electrons and holes, providing more active sites and enhancing the photocatalytic activity of CuWO4.
Article
Computer Science, Information Systems
William J. Milestone, Sergey A. Nikishin, R. P. Joshi
Summary: This study examines the possibility of pulse compression in carbon-doped PCSS devices for faster operation. The results show that an increase in carrier density can increase pulse compression and create pulse-widths that are smaller than the FWHM of the input optical excitation, which is beneficial for enhanced repetition rates.
Article
Chemistry, Physical
Yu-Xin Ye, Cheng Wen, Jinhui Pan, Jia-Wei Wang, Yuan-Jun Tong, Songbo Wei, Zhuofeng Ke, Long Jiang, Fang Zhu, Ningbo Zhou, Minjie Zhou, Jianqiao Xu, Gangfeng Ouyang
Summary: This study achieved efficient production of hydrogen peroxide at ambient conditions using an elaborately modified carbon nitride photocatalyst, presenting a potential example for truly sustainable and economical methods.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Multidisciplinary
Artem Grebenko, Anton Bubis, Konstantin Motovilov, Viacheslav Dremov, Evgeny Korostylev, Ivan Kindiak, Fedor S. Fedorov, Sergey Luchkin, Yuliya Zhuikova, Aleksandr Trofimenko, Gleb Filkov, Georgiy Sviridov, Andrey Ivanov, Jordan T. Dull, Rais Mozhchil, Andrey Ionov, Valery Varlamov, Barry P. Rand, Vitaly Podzorov, Albert G. Nasibulin
Summary: A new class of green and gentle lithographic resists has been developed, allowing compatibility with delicate materials and enabling fabrication of devices with sub-micron features. This approach opens up avenues for in-depth research of unconventional delicate materials at the nanoscale.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Yi-Shiuan Huang, Yang-Hao Chan, Guang-Yu Guo
Summary: We performed ab initio many-body calculations to study the exciton shift current in small-diameter zigzag BN nanotubes and single BN sheet. It was found that there is a large in-gap peak in the shift current spectrum in all studied BN systems due to the A exciton. The peak value of the excitonic shift current is more than three times larger than that of the quasiparticle shift current, and is attributed to the significant enhancement of the optical dipole matrix element by the A exciton. Importantly, the direction of the shift current in the BN nanotubes is independent of the tube chirality.
Article
Physics, Applied
Merwan Mokhtari, Philippe Pagnod-Rossiaux, Christophe Levallois, Francois Laruelle, Daniel T. Cassidy, Mauro Bettiati, Jean-Pierre Landesman
Summary: This study investigates the strain field in mesa structures for oxide-confined VCSELs using polarization-resolved micro-photoluminescence measurement. The spatial distribution of anisotropic strain in VCSEL structures is correlated with the degree of polarization of the photoluminescence. The DOP method allows sensitive measurements of mechanical strain accumulated in VCSEL devices during different fabrication steps.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Maciej J. Winiarski
Summary: This study investigated the electronic structures of ternary alloys of group III and rare earth nitrides, revealing that the introduction of rare earth ions can affect the band gap width. The findings suggest potential applications of these materials, encouraging further experimental investigations.
