Article
Engineering, Electrical & Electronic
Zhongming Zheng, Yang Mei, Hao Long, Jason Hoo, Shiping Guo, Qingxuan Li, Leiying Ying, Zhiwei Zheng, Baoping Zhang
Summary: An optically pumped AlGaN-based VCSEL laser in the deep ultraviolet range has been demonstrated, with a lasing wavelength of 275.91 nm, threshold power density of 1.21 MW/cm(2), and linewidth of 0.78 nm. The performance of this laser is believed to be enhanced by the high IQE of the AlGaN-based MQWs and improved fabrication processes.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Optics
Lars Persson, Filip Hjort, Giulia Cardinali, Johannes Enslin, Tim Kolbe, Tim Wernicke, Michael Kneissl, Joachim Ciers, Asa Haglund
Summary: A concept for achieving a temperature-stable lasing wavelength in VCSELs is proposed and demonstrated. By incorporating a dielectric material with a negative thermo-optic coefficient in the DBRs, the positive dn/dT of the semiconductor cavity can be compensated and the redshift of the lasing wavelength can be avoided. This concept is validated for optically-pumped VCSELs emitting at 310 nm, showing a maximum blueshift of less than 0.1 nm over an 80 degrees C range.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Electrical & Electronic
Xiaolang Qiu, Chao Wang, Jian Li, Chuanchuan Li, Xinyu Xie, Yongli Wang, Xin Wei
Summary: We designed and demonstrated a temperature-stable, wide-tuned, high-power VECSEL. By optimizing the quantum well and BF curve, we obtained a VECSEL with a wide adjustable range, high power, and temperature stability. This is of great significance for the design of VECSEL with wide tuning range, high power, and good temperature stability.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Yude Li, Zheng Li, Mei Chen, Jinglun Liu
Summary: The study introduces a folded resonator structure for VCSE diode lasers, where the reflective properties of VCSELs and the axis construction of the resonator ensure high-quality laser beam output.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Optics
Zhongming Zheng, Yukun Wang, Yang Mei, Hao Long, Leiying Ying, Zhiwei Zheng, Baoping Zhang
Summary: This study proposes a new periodic structure to replace the ITO current spreading layer in GaN-based VCSELs, aiming to lower the threshold and increase the laser power.
Article
Chemistry, Multidisciplinary
Qiuxue Fu, Yurun Sun, Suzhen Yu, Ancheng Wang, Jiajing Yin, Yongming Zhao, Jianrong Dong
Summary: Low threshold current and polarization-stabilized 795 nm VCSELs are fabricated by integrating a surface grating of high selectivity and reflectivity. A threshold current of 0.4 mA and an OPSR of 19.56 dB are obtained for the devices with a grating period of 500 nm, a grating depth of 150 nm, and a grating region diameter of 5 μm. The emission wavelength of 795 nm is achieved for a single transverse mode VCSEL at a temperature of 85°C and an injection current of 0.9 mA, while the threshold and output power depend on the size of the grating region.
Article
Engineering, Electrical & Electronic
Nusrat Jahan, William North, Pawel Strzebonski, Kent D. Choquette
Summary: This study reports and analyzes the supermode switching with current injection in coherently-coupled dual-element vertical cavity surface emitting laser arrays. The enhanced output power from in-phase or out-of-phase supermodes is confirmed when equal currents are injected into each array element. The switching of coherent supermodes from out-of-phase to in-phase is consistent with coupled mode theory and a 1-dimensional spatial supermode model, with calculated modal gain matching the observed switching behavior.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Optics
Zhao Fei Yun, L. Yan, Tang Zhi Ting, Ren Ao Bo, Wu Jiang
Summary: This study reports high-power multi-junction vertical-cavity surface-emitting lasers (VCSELs) that effectively suppress carrier leakage under high injection current and temperature. By optimizing the energy band structure of quaternary AlGaAsSb, a 12-nm-thick AlGaAsSb electron-blocking layer (EBL) was achieved with improved performance. The proposed EBL demonstrated enhanced output power and power conversion efficiency during room-temperature operation, while also exhibiting advantages over the original device during high-temperature operation.
Article
Chemistry, Multidisciplinary
Pan Fu, Pei-Nan Ni, Bo Wu, Xian-Zhi Pei, Qiu-Hua Wang, Pei-Pei Chen, Chen Xu, Qiang Kan, Wei-Guo Chu, Yi-Yang Xie
Summary: Metasurface polarization optics consisting of birefringent nano-antennas can be integrated with VCSEL platforms to achieve compact control over the phase and polarization properties of the laser. These integrated vector beams have the potential to revolutionize optical communications, laser manipulation, information encryption, and quantum optics by bypassing the need for multiple optical components and offering versatile functionalities.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Guanzhong Pan, Meng Xun, Xue Chen, Zhuangzhuang Zhao, Yun Sun, Jingtao Zhou, Dexin Wu
Summary: The study proposes high compactness Bessel beam devices based on vertical-cavity surface-emitting lasers (VCSELs) and microdielectric axicons made by Si3N4. Zero- and first-order Bessel beams can be obtained by engineering the lasing modes of the VCSELs, even if the device works at multimode.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Review
Materials Science, Multidisciplinary
Anas Skalli, Joshua Robertson, Dafydd Owen-Newns, Matej Hejda, Xavier Porte, Stephan Reitzenstein, Antonio Hurtado, Daniel Brunner
Summary: Photonic realizations of neural network computing hardware are a promising approach for future scalable neuromorphic computing. This review provides an overview of VCSELs and their integration with other photonic hardware to achieve high-performance artificial neurons, efficient and scalable neural network connections, and strategies for adjusting network connections during learning. VCSELs are highly energy efficient and ultra-fast, making them suitable for both all-optical and electro-optical photonic neurons.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Zhongming Zheng, Yukun Wang, Jason Hoo, Shiping Guo, Yang Mei, Hao Long, Leiying Ying, Zhiwei Zheng, Baoping Zhang
Summary: This study fabricated a high-quality AlGaN multiple quantum wells (MQWs) structure and analyzed it using X-ray diffraction (XRD) and photoluminescence (PL) measurements. The internal quantum efficiency of the MQWs was found to be as high as 62%, and radiative recombination dominated the emission of the MQWs at room temperature. Ultraviolet radiation C (UVC) VCSELs with lasing wavelengths of 275.91, 276.28, and 277.64 nm were successfully fabricated, with a record low threshold power density of 0.79 MW / cm².
SCIENCE CHINA-MATERIALS
(2023)
Article
Optics
Jing Zhang, Chenxi Hao, Wanhua Zheng, Dieter Bimberg, Anjin Liu
Summary: We experimentally demonstrate electrically injected vertical-cavity surface-emitting lasers (VCSELs) with post-supported high-contrast gratings (HCGs) at 940 nm for the first time. The HCG-VCSELs, fabricated without critical point drying, achieve a low threshold current and high side-mode suppression ratio. The design of the HCG-VCSELs enhances the relaxation resonance frequency and enables high-speed modulation. This research has significant practical applications and promising prospects.
PHOTONICS RESEARCH
(2022)
Article
Engineering, Environmental
Chunhu Zhao, Jiahua Tao, Jiao Tian, Guoen Weng, Huimin Liu, Yuejun Liu, Jiyu Yan, Shengjie Chen, Yanlin Pan, Xiaobo Hu, Shaoqiang Chen, Hidefumi Akiyama, Junhao Chu
Summary: Perovskite nanocrystals have shown great potential as optical gain materials for laser applications. This study successfully demonstrated high performance single-mode VCSELs using CsPbBr3 PNCs synthesized via a facile strategy, showing excellent single-mode lasing and high spontaneous emission coupling factor. The ultrafast decay of stimulated emission in VCSELs is attributed to the electron hole plasma mechanism.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Tanja Finke, Vitalii Sichkovskyi, Johann Peter Reithmaier
Summary: In this study, an optically pumped vertical external-cavity surface-emitting laser based on quantum dots with high optical gain was demonstrated. By optimizing the photoluminescence emission of the quantum dots and reducing non-radiative recombination centers, high output power efficiency was achieved. Analysis was also conducted on the number of quantum dot layers, the heat sink temperature, and the heat spreader material to improve the performance of the laser.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Jakub Jurczyk, Christopher R. Brewer, Olivia M. Hawkins, Mikhail N. Polyakov, Czeslaw Kapusta, Lisa McElwee-White, Ivo Utke
ACS APPLIED MATERIALS & INTERFACES
(2019)
Review
Chemistry, Analytical
Harald Plank, Robert Winkler, Christian H. Schwalb, Johanna Huetner, Jason D. Fowlkes, Philip D. Rack, Ivo Utke, Michael Huth
Article
Chemistry, Multidisciplinary
Mikko Ruoho, Janne-Petteri Niemela, Carlos Guerra-Nunez, Natalia Tarasiuk, Georgina Robertson, Aidan A. Taylor, Xavier Maeder, Czeslaw Kapusta, Johann Michler, Ivo Utke
Article
Engineering, Chemical
Wojciech Szmyt, Carlos Guerra-Nunez, Clemens Dransfeld, Ivo Utke
Summary: This study identified the specific parameters affecting gas diffusion kinetics and provided analytical expressions to describe gas transport in these structures. The analytical solutions were confirmed through Monte Carlo simulations, and the applicability of these findings in other fields was highlighted.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Physical
Krzysztof Wieczerzak, Agnieszka Priebe, Ivo Utke, Johann Michler
Summary: This study discusses the practical aspects of fluorine gas-assisted FIB-TOF-SIMS analysis, demonstrating significantly enhanced SIMS signals and reduced negative effects on the sample surface.
CHEMISTRY OF MATERIALS
(2021)
Article
Thermodynamics
Jakub Jurczyk, Cristiano Glessi, Katarzyna Madajska, Luisa Berger, Jeroen Ingolf Ketele Nyrud, Iwona Szymanska, Czeslaw Kapusta, Mats Tilset, Ivo Utke
Summary: The study compared vacuum and ambient pressure inert gas thermogravimetry on silver carboxylates compounds, revealing significant differences in sublimation behavior and thermal stability. Vacuum thermogravimetry was found to be a fast method for pre-screening low-volatility precursors, which is important for thin film synthesis and nanomanufacturing processes.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Nanoscience & Nanotechnology
Agnieszka Priebe, Laszlo Petho, Emese Huszar, Tianle Xie, Ivo Utke, Johann Michler
Summary: This work demonstrates the potential of high vacuum-compatible TOF-SIMS detectors integrated within FIB instruments for precise and fast chemical characterization of thin films buried deep under the sample surface. By co-injecting fluorine gas during sample surface sputtering, typical issues of TOF-SIMS technique were solved, leading to impressive achievements in detecting and spatially resolving thin films with small compositional differences.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Kamil Goc, Janusz Przewoznik, Katarzyna Witulska, Leszek Chlubny, Waldemar Tokarz, Tomasz Straczek, Jan Marek Michalik, Jakub Jurczyk, Ivo Utke, Jerzy Lis, Czeslaw Kapusta
Summary: This study examined the properties of Ti3Al1-xSixC2 MAX-phase alloys, showing good crystal structure, metallic properties with high residual resistivity, and a small positive magnetoresistance effect. Silicon doping had a weak impact on resistivity while the magnetoresistance exhibited a quadratic dependence on the magnetic field. Specific heat data indicated slight variations in Debye temperatures and Sommerfeld coefficient values with changes in Si content. Band structure calculations supported experimental results, highlighting the contribution of Al and Si s-electrons to metallic conductivity.
Article
Chemistry, Analytical
Luisa Berger, Jakub Jurczyk, Katarzyna Madajska, Iwona B. Szymanska, Patrik Hoffmann, Ivo Utke
Summary: A combined approach of FEBID and direct electron beam lithography (D-EBL) was presented for high-resolution metallic nanostructures fabrication. By utilizing a low-volatility copper precursor and focused electron beam irradiation, the method promises fast and easy fabrication results. The study also investigated the influence of electron scattering within the substrate and implementing a post-purification protocol to achieve high-purity copper crystals.
Article
Chemistry, Physical
Wojciech Szmyt, Carlos Guerra-Nunez, Lukas Huber, Clemens Dransfeld, Ivo Utke
Summary: This study explores the direct quantitative relationship between diffusion- and reaction-limited ALD regimes with the width of the reaction zone and the profile of chemisorption coverage in a single-cycle ALD, introducing a new parametrization based on the natural system of units for the system.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Agnieszka Priebe, Bryan Dousse, Chia-Yu Tzou, Georgios Papadopoulos, Ivo Utke, Abdelhak Bensaoula, Johann Michler, Carlos Guerra-Nunez
Summary: This article presents the potential of integrating a time-of-flight mass spectrometer (TOFMS) with atomic layer deposition (ALD) for real-time control of thin-film fabrication processes. The technique allows for parallel detection and in situ chemical data acquisition, enabling immediate modifications to the deposition parameters.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Jakub Jurczyk, Lex Pillatsch, Luisa Berger, Agnieszka Priebe, Katarzyna Madajska, Czeslaw Kapusta, Iwona B. Szymanska, Johann Michler, Ivo Utke
Summary: This study developed a method called focused-electron-beam-induced mass spectrometry (FEBiMS) for analyzing the fragmentation products of metalorganic compounds under electron irradiation. The results showed that FEBiMS is capable of investigating the fragmentation process of electron-sensitive materials within the energy range of scanning electron microscopes and has potential applications in studying fundamental and process parameters in various nanotechnology fields.
Article
Materials Science, Multidisciplinary
Thomas Edward James Edwards, Tianle Xie, Nicolo Maria della Ventura, Daniele Casari, Carlos Guerra, Emese Huszar, Xavier Maeder, Johann Jakob Schwiedrzik, Ivo Utke, Laszlo Petho, Johann Michler
Summary: Physical vapour deposition combined with atomic layer deposition was used to design a model system of ultrafine-grained aluminum with a narrow grain size distribution. The study investigated the strengthening mechanisms of ultrathin oxide layers in a metal multilayer structure. Experimental results showed that the strengthening effect of the oxide layer was effective even at a thickness of 0.5 nm.
Article
Chemistry, Multidisciplinary
Jakub Jurczyk, Katja Hoeflich, Katarzyna Madajska, Luisa Berger, Leo Brockhuis, Thomas Edward James Edwards, Czeslaw Kapusta, Iwona B. Szymanska, Ivo Utke
Summary: Gas-assisted focused electron-beam-induced deposition is a versatile tool for direct writing of complex-shaped nanostructures with unprecedented shape fidelity and resolution. The direct electron beam writing of silver is still in its early stage of development, and the potential precursors for focused electron-beam-induced deposition of silver are examined and compared in this study.
Article
Chemistry, Inorganic & Nuclear
Janne-Petteri Niemela, Nadia Rohbeck, Johann Michler, Ivo Utke
DALTON TRANSACTIONS
(2020)
Article
Chemistry, Multidisciplinary
Laetitia Bardet, Herve Roussel, Stefano Saroglia, Masoud Akbari, David Munoz-Rojas, Carmen Jimenez, Aurore Denneulin, Daniel Bellet
Summary: The thermal instability of silver nanowires leads to increased electrical resistance in AgNW networks. Understanding the relationship between structural and electrical properties of AgNW networks is crucial for their integration as transparent electrodes in flexible optoelectronics. In situ X-ray diffraction measurements were used to study the crystallographic evolution of Ag-specific Bragg peaks during thermal ramping, revealing differences in thermal and structural transitions between bare and SnO2-coated AgNW networks.
Article
Chemistry, Multidisciplinary
Nathalia Cancino-Fuentes, Arnau Manasanch, Joana Covelo, Alex Suarez-Perez, Enrique Fernandez, Stratis Matsoukis, Christoph Guger, Xavi Illa, Anton Guimera-Brunet, Maria V. Sanchez-Vives
Summary: This study provides a comprehensive characterization of graphene-based solution-gated field-effect transistors (gSGFETs) for brain recordings, highlighting their potential clinical applications.
Article
Chemistry, Multidisciplinary
Sikandar Aftab, Hailiang Liu, Dhanasekaran Vikraman, Sajjad Hussain, Jungwon Kang, Abdullah A. Al-Kahtani
Summary: This study examines the effects of hybrid nanoparticles made of NiO@rGO and NiO@CNT on the active layers of polymer solar cells and X-ray photodetectors. The findings show that these hybrid nanoparticles can enhance the charge carrier capacities and exciton dissociation properties of the active layers. Among the tested configurations, the NiO@CNT device demonstrates superior performance in converting sunlight into electricity, and achieves the best sensitivity for X-ray detection.
Article
Chemistry, Multidisciplinary
Hyo Jung Shin, Seung Gyu Choi, Fengrui Qu, Min-Hee Yi, Choong-Hyun Lee, Sang Ryong Kim, Hyeong-Geug Kim, Jaewon Beom, Yoonyoung Yi, Do Kyung Kim, Eun-Hye Joe, Hee-Jung Song, Yonghyun Kim, Dong Woon Kim
Summary: This study investigates the role of SOX9 in reactive astrocytes following ischemic brain damage using a PLGA nanoparticle plasmid delivery system. The results demonstrate that PLGA nanoparticles can reduce ischemia-induced neurological deficits and infarct volume, providing a potential opportunity for stroke treatment.
Article
Chemistry, Multidisciplinary
Anurag Chaudhury, Koushik Debnath, Nikhil R. Jana, Jaydeep K. Basu
Summary: The study investigates the interaction between nanoparticles and cell membranes, and identifies key parameters, including charge, crowding, and membrane fluidity, that determine the adsorbed concentration and unbinding transition of nanoparticles.
Article
Chemistry, Multidisciplinary
Sina Sadeghi, Fazel Bateni, Taekhoon Kim, Dae Yong Son, Jeffrey A. Bennett, Negin Orouji, Venkat S. Punati, Christine Stark, Teagan D. Cerra, Rami Awad, Fernando Delgado-Licona, Jinge Xu, Nikolai Mukhin, Hannah Dickerson, Kristofer G. Reyes, Milad Abolhasani
Summary: In this study, an autonomous approach for the development of lead-free metal halide perovskite nanocrystals is presented, which integrates a modular microfluidic platform with machine learning-assisted synthesis modeling. This approach enables rapid and optimized synthesis of copper-based lead-free nanocrystals.
Article
Chemistry, Multidisciplinary
Zahir Abbas, Nissar Hussain, Surender Kumar, Shaikh M. Mobin
Summary: The rational construction of free-standing and flexible electrodes for electrochemical energy storage devices is an emerging research focus. In this study, a redox-active metal-organic framework (MOF) was prepared on carbon nanofibers using an in situ approach, resulting in a flexible electrode with high redox-active behavior and unique properties such as high flexibility and lightweight. The prepared electrode showed excellent cyclic retention and rate capability in supercapacitor applications. Additionally, it could be used as a freestanding electrode in flexible devices at different bending angles.
Article
Chemistry, Multidisciplinary
Lishan Zhang, Xiaoting Zhang, Hui Ran, Ze Chen, Yicheng Ye, Jiamiao Jiang, Ziwei Hu, Miral Azechi, Fei Peng, Hao Tian, Zhili Xu, Yingfeng Tu
Summary: Photodynamic therapy (PDT) is a promising local treatment modality in cancer therapy, but its therapeutic efficacy is restricted by ineffective delivery of photosensitizers and tumor hypoxia. In this study, a phototactic Chlorella-based near-infrared (NIR) driven green affording-oxygen microrobot system was developed for enhanced PDT. The system exhibited desirable phototaxis and continuous oxygen generation, leading to the inhibition of tumor growth in mice. This study demonstrates the potential of using a light-driven green affording-oxygen microrobot to enhance photodynamic therapy.
Article
Chemistry, Multidisciplinary
Yujin Li, Jing Xu, Xinqi Luo, Futing Wang, Zhong Dong, Ke-Jing Huang, Chengjie Hu, Mengyi Hou, Ren Cai
Summary: In this study, hollow heterostructured materials were constructed using an innovative template-engaged method as cathodes for zinc-ion batteries. The materials exhibited fast Zn2+ transport channels, improved electrical conductivity, and controlled volume expansion during cycling. The designed structure allowed for an admirable reversible capacity and high coulombic efficiency.
Article
Chemistry, Multidisciplinary
Paritosh Mahato, Shashi Shekhar, Rahul Yadav, Saptarshi Mukherjee
Summary: This study comprehensively elucidates the role of the core and electrostatic surface of metal nanoclusters in catalytic reduction reactions. The electrostatic surface dramatically modulates the reactivity of metal nanoclusters.
Article
Chemistry, Multidisciplinary
Pei Liu, Mengdi Liang, Zhengwei Liu, Haiyu Long, Han Cheng, Jiahe Su, Zhongbiao Tan, Xuewen He, Min Sun, Xiangqian Li, Shuai He
Summary: This study demonstrates a simple and environmentally-friendly method for the synthesis of zinc oxide nanozymes (ZnO NZs) using wasted hop extract (WHE). The WHE-ZnO NZs exhibit exceptional peroxidase-like activity and serve as effective catalysts for the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). In addition, a straightforward colorimetric technique for detecting both H2O2 and glucose was developed using the WHE-ZnO NZs as peroxidase-like catalysts.
Article
Chemistry, Multidisciplinary
Hyunkyu Oh, Young Jun Lee, Eun Ji Kim, Jinseok Park, Hee-Eun Kim, Hyunsoo Lee, Hyunjoo Lee, Bumjoon J. Kim
Summary: Mesoporous carbon particles have unique structural properties that make them suitable as support materials for catalytic applications. This study investigates the impact of channel nanostructures on the catalytic activity of porous carbon particles (PCPs) by fabricating PCPs with controlled channel exposure on the carbon surface. The results show that PCPs with highly open channel nanostructures exhibit significantly higher catalytic activity compared to those with closed channel nanostructures.
Article
Chemistry, Multidisciplinary
Yunjie Lu, Zhaohui Li, Zewei Li, Shihao Zhou, Ning Zhang, Jianming Zhang, Lu Zong
Summary: A tough, long-lasting adhesive and highly conductive nanocomposite hydrogel (PACPH) was fabricated via the synergy of interfacial entanglement and adhesion group densification. PACPH possesses excellent mechanical properties, interfacial adhesion strength, and conductivity, making it a promising material for long-term monitoring of human activities and electrocardiogram signals.
Article
Chemistry, Multidisciplinary
Zichao Wei, Audrey Vandergriff, Chung-Hao Liu, Maham Liaqat, Mu-Ping Nieh, Yu Lei, Jie He
Summary: We have developed a simple method to prepare polymer-grafted plasmonic metal nanoparticles with pH-responsive surface-enhanced Raman scattering. By using pH-responsive polymers as ligands, the aggregation of nanoparticles can be controlled, leading to enhanced SERS. The pH-responsive polymer-grafted nanoparticles show high reproducibility and sensitivity in solution, providing a novel approach for SERS without the need for sample pre-concentration.
Article
Chemistry, Multidisciplinary
Melis Ozge Alas Colak, Ahmet Gungor, Merve Buldu Akturk, Emre Erdem, Rukan Genc
Summary: This research investigates the effect of functionalizing carbon dots with hydroxyl polymers on their performance as electrode materials in a supercapacitor. The results show that the functionalized carbon dots exhibit excellent electrochemical performance and improved stability.