Article
Chemistry, Physical
Yuanyuan Li, Xiaoyu Liu, Tianyuan Liang, Jiyang Fan
Summary: The surface of SiC quantum dots is a complex two-dimensional system with abundant surface reconstruction and passivation, affecting their chemistry and photophysics. This study reports the novel yellow fluorescence of colloidal SiC QDs in the quantum confinement regime, which decays much slower compared to previously observed blue-green fluorescence. The calculations show that the yellow fluorescence originates from trapped surface states at the Si=O bond, providing a better understanding of the surface properties of SiC QDs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Optics
Dongke Li, Jiaming Chen, Teng Sun, Yangyi Zhang, Jun Xu, Wei Li, Kunji Chen
Summary: Phosphorus/boron co-doping in Si quantum dots/SiO2 multilayers enhances subband light emission, with increasing B co-doping ratio resulting in improved emission intensity nearly two orders of magnitude stronger than solely P-doped samples. This enhancement is attributed to B dopants passivating surface dangling bonds, leading to suppressed phosphorus-related deep level emission and appearance of emission centered around 1400 nm in high B co-doping ratios.
Article
Chemistry, Physical
Dongke Li, Jiaming Chen, Zhaoguo Xue, Teng Sun, Junnan Han, Wanghua Chen, Etienne Talbot, Remi Demoulin, Wei Li, Jun Xu, Kunji Chen
Summary: Understanding the distribution and behavior of dopants in silicon nanocrystals is crucial for achieving controllable doping at the nanoscale and developing next-generation optoelectronic devices. This study investigates the atomic-scale distributions of phosphorus and boron dopants in silicon nanocrystal multilayers. The results show that phosphorus dopants mainly concentrate on the surfaces of silicon nanocrystals to passivate dangling bonds and provide free electrons, while boron dopants exhibit a different distribution pattern, forming a dopant-shell covering on the surfaces of silicon nanocrystals and leading to damage in the crystalline lattice.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Alfredo Morales-Sanchez, Maria Antonia Cardona-Castro, Liliana Licea-Jimenez, Liliana Palacios-Huerta, Antonio Coyopol, Sergio Alfonso Perez-Garcia, Jaime Alvarez-Quintana, Mario Moreno
Summary: In this work, a correlation between the composition and the microstructural and optical properties of luminescent porous silicon (PSi) films is shown. The use of nitric acid enhances the photoluminescence intensity of PSi samples. Changing the concentration ratio of the electrolyte solution can modify the size of silicon nanocrystals and the emission wavelength. These findings are important for understanding the properties and applications of PSi.
Review
Chemistry, Multidisciplinary
Gill M. Biesold, Shuang Liang, Blair Brettmann, Naresh Thadhani, Zhitao Kang, Zhiqun Lin
Summary: This review introduces colloidal semiconductor nanocrystals and examines the effects of uniform pressure on the optical properties of various semiconductor nanocrystals, summarizing the optical properties of these nanocrystals under static and dynamic pressure. Future research directions and applications utilizing the pressure-dependent optical properties of semiconductor nanocrystals are also discussed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Manmohan Jain, J. R. Ramos-Serrano, Ateet Dutt, Yasuhiro Matsumoto
Summary: This study focused on the deposition of SiOxCy thin films using the O-Cat CVD technique, with an emphasis on the influence of deposition time on the optical properties. The chemical composition of the SiOxCy matrix was analyzed using FTIR and XPS techniques. The results demonstrated that intense photoluminescence emissions could be observed at low substrate temperatures, providing insights into the defect mechanisms and spectral shifts in the PL emissions.
Article
Optics
Ronja Koethemann, Christian Golla, Hong Qu, Cedrik Meier
Summary: This study investigates the influence of gold nanoantennas on the photoluminescence signal of silicon nanocrystals. By integrating gold nanoantennas into a layered system containing silicon nanocrystals, the photoluminescence signal can be manipulated in terms of attenuation or enhancement. Additionally, the impact of grating coupling and the number of antennas per antenna array on the amplification of the photoluminescence signal is examined.
Article
Chemistry, Physical
Yuping Xu, Yunzi Xin, Takashi Shirai
Summary: Visible photoluminescent silicon nanocrystals capped with hydrophobic surface were successfully synthesized using a novel one-step bottom-up approach. The synthesized Si NCs have an average size of 3.4 nm and exhibit visible photoluminescence with a high absolute quantum yield of 17%, possibly due to the efficient hydrophobic surface capping on the Si NCs.
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Jiawen Zhou, Cheng Wang, Ming Song, Xianhui Chen, Weidong Xia
Summary: An atmospheric non-thermal arc plasma source based on magnetically stabilized gliding arc discharge was developed for the continuous preparation of ultrafine amorphous silicon carbide (a-SiC) nanoparticles via hexamethyldisilane decomposition. The synthesized nanoparticles showed strong blue-green light emission and had abundant functional groups and oxidized overlayers on their surface. Low input energy favored the synthesis of a-SiC nanoparticles, while high input energy promoted the transition from amorphous structure to b-SiC.
Article
Physics, Applied
Juliusz Kruszelnicki, Runchu Ma, Mark J. Kushner
Summary: The study investigates the propagation of atmospheric pressure plasmas through porous dielectric materials, revealing the significant role of photoionization and the impact of pore-chain orientation with respect to the applied electric field on plasma generation and distribution of reactive species to pore surfaces.
JOURNAL OF APPLIED PHYSICS
(2021)
Review
Chemistry, Multidisciplinary
Yize Su, Chenhao Wang, Zijian Hong, Wei Sun
Summary: Silicon nanocrystals have drawn significant attention in recent decades for their unique luminescent properties, with thermal disproportionation method offering precise control over their size and structure, showing promising industrial applications. Research has shown that factors such as temperature, Si/O ratio, and surface groups play a crucial role in determining the properties of silicon nanocrystals.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Applied
Anna Dzimitrowicz, Piotr Jamroz, Piotr Cyganowski, Aleksandra Bielawska-Pohl, Aleksandra Klimczak, Pawel Pohl
Summary: By controlling cold atmospheric pressure plasma (CAPP) treatment, the element composition pattern and phenolic compound content of beetroot juice were altered, inhibiting the proliferation of colorectal adenocarcinoma cell lines while exhibiting non-cytotoxic effects on non-malignant endothelial cells, resulting in a safe-to-consume beetroot juice with improved nutritional quality.
Article
Nanoscience & Nanotechnology
Fei Kong, Mingming Zhao, Cheng Zhang, Chengyan Ren, Kostya Ken Ostrikov, Tao Shao
Summary: The study successfully addressed the issues of flashover performance and stability of high-voltage, high-power FGM-based electric insulation by interfacing rutile and anatase TiO2 layers using atmospheric pressure plasma processing. The FGM showed significant improvements in reducing electric field and increasing flashover voltage, along with exceptional long-term stability. The mechanisms of plasma-enabled graded layer formation were presented, offering potential for precise engineering of FGMs for diverse applications in various fields.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Diana Nesheva, Zsolt Fogarassy, Margit Fabian, Temenuga Hristova-Vasileva, Attila Sulyok, Irina Bineva, Evgenia Valcheva, Krassimira Antonova, Peter Petrik
Summary: This research focuses on the reformation of semiconductor nanocrystals in dielectric matrices under electron irradiation, as well as the influence of neutron irradiation on substoichiometric silicon oxide. The study shows that neutron irradiation can induce phase separation in homogeneous films and decrease the volume fraction of amorphous silicon phase in inhomogeneous films.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Chi-Chin Wu, John Derek Demaree, Amanda Weerasooriya, Andres Bujanda, Eric Jason Robinette
Summary: This study successfully improved the surface wettability and adhesive strength of nylon 66 by using different plasma treatment methods. The surface hydrophilicity of nylon 66 was significantly enhanced after plasma treatment, leading to improved adhesive strength.
Article
Engineering, Environmental
Rezvan Hosseini Rad, Volker Brueser, Milko Schiorlin, Jan Schaefer, Ronny Brandenburg
Summary: CO2 splitting in a dielectric barrier discharge (DBD) is investigated using both empty and packed bed reactors with and without cerium oxide catalyst. The DBDs are operated at pressures up to 2 bar, with the addition of argon to reduce breakdown voltage. The electrical characteristics of the discharge are studied, along with the CO2 dissociation. Increasing pressure requires a higher minimum sustaining voltage amplitude, but the optimum power input depends on pressure and gas composition. Adding ceria-coated glass spheres improves reactor performance.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Luka Hansen, Niklas Kohlmann, Lorenz Kienle, Holger Kersten
Summary: A custom-built atmospheric pressure direct current microplasma discharge was designed using Au coated Si3N4 transmission electron microscopy grids as electrodes for direct imaging of the plasma treated surfaces. Significant differences were observed between the anode and cathode, as well as between Ar or He operation of the microplasma, from examination of the electrode surfaces using light microscopy. Scanning electron microscopy and TEM imaging provided details of grain growth and changes in surface morphology, revealing the effects of energy fluxes and ions on surface modifications.
Article
Chemistry, Multidisciplinary
Oguz Han Asnaz, Jonas Drewes, Marie Elis, Thomas Strunskus, Franko Greiner, Oleksandr Polonskyi, Franz Faupel, Lorenz Kienle, Alexander Vahl, Jan Benedikt
Summary: A novel combined setup of a Haberland type gas aggregation source and a secondary radio frequency discharge is used to generate, confine, and coat nanoparticles over much longer time scales than traditional in-flight treatment. The process is precisely monitored using localized surface plasmon resonance and Fourier-transform infrared spectroscopy as in situ diagnostics. Surface coating is shown to occur in two phases: first, singular seeds appear on the particle surface which then grow to cover the entire particle surface over 3 to 5 minutes.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Igor Barg, Niklas Kohlmann, Florian Rasch, Thomas Strunskus, Rainer Adelung, Lorenz Kienle, Franz Faupel, Stefan Schroeder, Fabian Schuett
Summary: This work demonstrates a novel concept for the development of strain-invariant, highly elastic and highly water stable all-organic soft conductors, overcoming the limitations of previous strain-invariant soft conductors. The thin film structure has highly hydrophobic properties, resulting in stable electrical properties even when immersed in water for a month.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Optics
T. A. Hahn, J. Benedikt, H. Kersten
Summary: The absolute densities of O and O-3 in the effluent of a kINPen are measured using molecular beam mass spectrometry. The use of a nitrogen gas curtain and different gas mixtures ensure stable conditions and higher densities of reactive species are generated when operated in argon. A new molecular beam chopper design has also been successfully tested in the setup.
EUROPEAN PHYSICAL JOURNAL D
(2023)
Article
Chemistry, Physical
He Li, Sadegh Askari, Jihao Wang, Niklas Wolff, Malte Behrens, Lorenz Kienle, Jan Benedikt
Summary: A noble-metal-free bifunctional electrocatalyst was developed through a facile strategy for rechargeable zinc-air batteries. The nitrogen-doped NiCo2O4 nanostructures on carbon paper exhibited enhanced electrocatalytic activities for oxygen evolution and reduction reactions. The plasma treatment optimized the N doping process without changing the morphology and specific surface area of the catalyst. The resulting air cathode showed improved stability and performance compared to noble-metal catalyst counterparts.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Physics, Multidisciplinary
F. Matejka, P. Galar, J. Khun, V Scholtz, K. Kusova
Summary: Plasma activated water (PAW), traditionally used for decontamination and disinfection, can also be beneficial for tailoring the surface chemistry of semiconductor nanostructures when containing a high concentration of nitrogen-related species (HiN:PAW). The pathways leading to the production of HiN:PAW are investigated by monitoring the composition of PAW and the concentration of selected species in the discharge under various conditions. The presence of a barrier area in the discharge reactor is identified as a key factor for the production of HiN:PAW.
Article
Chemistry, Physical
Nijad Ishak, Dominik Martynek, Jeyalakshmi Velu, Roman Bleha, Pavel Galar, Miroslav Soos
Summary: The core objectives of this study were efficient water decontamination and bacterial eradication. These objectives were achieved through the synthesis of a graphitic carbon nitride photocatalyst modified with a combination of carbon and iron oxide. The photocatalyst showed excellent activity, stability, and reusability.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Physical
Tomas Popelar, Pavel Galar, Filip Matejka, Giacomo Morselli, Paola Ceroni, Katerina Kusova
Summary: Silicon quantum dots (SiQDs) have potential for light emission, but the efficiency is hindered by dark quantum dots. We experimentally determine the dependence of radiative lifetimes on emission photon energy and use this to quantify the internal photoluminescence quantum yield. This approach can be applied by other researchers to study nonradiative processes and dark quantum dots. Additionally, we observe that the decay of SiQDs' photoluminescence can be non-single-exponential, possibly due to natural variation in radiative lifetimes. Average lifetimes are emphasized as an important quantity for characterizing photoluminescence decays in the absence of a widely accepted physical model.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Lena M. Saure, Niklas Kohlmann, Haoyi Qiu, Shwetha Shetty, Ali Shaygan Nia, Narayanan Ravishankar, Xinliang Feng, Alexander Szameit, Lorenz Kienle, Rainer Adelung, Fabian Schuett
Summary: This study presents a fabrication concept for highly porous photothermal hybrid aeromaterials, which show an ultrarapid and volumetric photothermal response. By using light-scattering framework structures and functionalized reduced graphene oxide nanosheets, the volumetric photothermal enhancement is achieved.