Photoluminescence Study of In-Situ Rare Earth Doped PVT-Grown SiC Single Crystals

2005 ◽  
Vol 483-485 ◽  
pp. 445-448 ◽  
Author(s):  
Holger Schmitt ◽  
Ralf Müller ◽  
Manfred Maier ◽  
Albrecht Winnacker ◽  
Peter J. Wellmann
Keyword(s):  
Bulk Crystals ◽  
Photoluminescence Study ◽  
Co Doping ◽  
As Doping ◽  
Stabilizing Effect ◽  
Luminescence Yield ◽  
Secondary Ion ◽  
Rare Earth Doped ◽  
Co Doped

Several SiC bulk crystals were grown with erbium and ytterbium as doping materials. Erbium contents determined by secondary ion mass spectroscopy (SIMS) ranged from 1.2 · 1014 cm-3 to 1.04 · 1015 cm-3, while ytterbium contents were below SIMS detection limit. Photoluminescence (PL) investigations of the characteristic 4f-4f-transition lines revealed a reduced luminescence yield in highly nitrogen and aluminum co-doped samples. Also, samples without intentional co-doping grown on the C-face showed less luminescence intensity than those grown on the Si-face. A stabilizing effect of erbium doping on the 4H polytype was observed.

Promoting Hydrogen Evolution of g-C3N4 Based Photocatalyst by Indium and Phosphorus Co-doping

2021 ◽  
Author(s):  
Xiao-Hang Yang ◽  
Chi Cao ◽  
Zilong Guo ◽  
Xiaoyu Zhang ◽  
Yaxin Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Post Treatment ◽  
Experimental Results ◽  
Indium Chloride ◽  
Co Doping ◽  
In Situ Copolymerization ◽  
Co Doped

Indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of indium doped g-C3N4 photocatalyst (In-g-C3N4) derived from in-situ copolymerization of dicyandiamide and indium chloride. The experimental results...

Growth of Low Resistivity n-Type 4H-SiC Bulk Crystals by Sublimation Method Using Co-Doping Technique

2014 ◽  
Vol 778-780 ◽  
pp. 47-50 ◽  
Author(s):  
Tomohisa Kato ◽  
Kazuma Eto ◽  
Satoru Takagi ◽  
Tomonori Miura ◽  
Yasushi Urakami ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Bulk Crystals ◽  
Low Resistivity ◽  
Co Doping ◽  
N Concentration ◽  
Sublimation Method ◽  
Doping Technique ◽  
Co Doped

The nitrogen (N) and aluminum (Al) co-doped growth of n-type 4H-SiC bulk crystals were performed by sublimation method. In the co-doping growth, we achieved the lowest resistivity of 6.9mWcm, and we also confirmed phenomenon of stacking faults suppression in spite of high N concentration more than 8 x 1019cm-3.

scholarly journals Structural and Photoluminescence Investigations of Tb3+/Eu3+ Co-Doped Silicate Sol-Gel Glass-Ceramics Containing CaF2 Nanocrystals

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 754
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Joanna Pisarska ◽  
Wojciech A. Pisarski
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Near Ultraviolet ◽  
Transmission Electron ◽  
Co Doped

In this work, the series of Tb3+/Eu3+ co-doped xerogels and derivative glass-ceramics containing CaF2 nanocrystals were prepared and characterized. The in situ formation of fluoride crystals was verified by an X-ray diffraction technique (XRD) and transmission electron microscopy (TEM). The studies of the Tb3+/Eu3+ energy transfer (ET) process were performed based on excitation and emission spectra along with luminescence decay analysis. According to emission spectra recorded under near-ultraviolet (NUV) excitation (351 nm, 7F6 → 5L9 transition of Tb3+), the mutual coexistence of the 5D4 → 7FJ (J = 6–3) (Tb3+) and the 5D0 → 7FJ (J = 0–4) (Eu3+) luminescence bands was clearly observed. The co-doping also resulted in gradual shortening of a lifetime from the 5D4 state of Tb3+ ions, and the ET efficiencies were varied from ηET = 11.9% (Tb3+:Eu3+ = 1:0.5) to ηET = 22.9% (Tb3+:Eu3+ = 1:2) for xerogels, and from ηET = 25.7% (Tb3+:Eu3+ = 1:0.5) up to ηET = 67.4% (Tb3+:Eu3+ = 1:2) for glass-ceramics. Performed decay analysis from the 5D0 (Eu3+) and the 5D4 (Tb3+) state revealed a correlation with the change in Tb3+–Eu3+ and Eu3+–Eu3+ interionic distances resulting from both the variable Tb3+:Eu3+ molar ratio and their partial segregation in CaF2 nanophase.

Photoluminescence Study of In-Situ Rare Earth Doped PVT-Grown SiC Single Crystals

2005 ◽  
pp. 445-448
Author(s):  
Holger Schmitt ◽  
Ralf Müller ◽  
Manfred Maier ◽  
Albrecht Winnacker ◽  
Peter J. Wellmann
Keyword(s):  
Rare Earth ◽  
Single Crystals ◽  
Photoluminescence Study ◽  
Rare Earth Doped

Synthesis of Eu2+, Dy3+ Co-Doped Mal2O4 Phosphor (M = Ba, Sr) by In Situ Self-Propagating High Temperature Synthesis

2012 ◽  
Vol 626 ◽  
pp. 908-912
Author(s):  
Taschaporn Sathaporn ◽  
Sutham Niyomwas
Keyword(s):  
High Temperature ◽  
Broad Band ◽  
Rare Earth Ions ◽  
Temperature Synthesis ◽  
Co Doping ◽  
High Temperature Synthesis ◽  
Excited Luminescence ◽  
Co Doped ◽  
Shs Method

Eu2+, Dy3+ co-doped alkaline earth aluminates MAl2O4: Eu2+, Dy3+ (M = Ba, Sr) have been prepared by in situ self-propagating high temperature synthesis (SHS) method. The influence of co-doping rare earth ions (Eu2+, Dy3+) on the luminescence of MAl2O4:Eu2+, Dy3+ were described in this study. The particles morphology, photoluminescence and afterglow properties of the phosphors were studied. Broad band UV excited luminescence was observed for BaAl2O4:Eu2+, Dy3+ and SrAl2O4:Eu2+, Dy3+ in the green region peak at max = 503 nm and 523 nm, respectively. The dopant (Eu2+) and co-dopant (Dy3+) concentrations affect the crystallinity and luminescence properties of the materials.

scholarly journals Hydrothermal Synthesis of Nitrogen, Boron Co-Doped Graphene with Enhanced Electro-Catalytic Activity for Cymoxanil Detection

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6630
Author(s):  
Codruța Varodi ◽  
Florina Pogăcean ◽  
Maria Coros ◽  
Lidia Magerusan ◽  
Raluca-Ioana Stefan-van Staden ◽  
...  
Keyword(s):  
Standard Addition ◽  
Xrd Analysis ◽  
Current Increase ◽  
Peak Current ◽  
Co Doping ◽  
As Doping ◽  
Graphene Sample ◽  
First Case ◽  
Doped Graphene ◽  
Co Doped

A sample of nitrogen and boron co-doped graphene (NB-Gr) was obtained by the hydrothermal method using urea and boric acid as doping sources. According to XRD analysis, the NB-Gr sample was formed by five-layer graphene. In addition, the XPS analysis confirmed the nitrogen and boron co-doping of the graphene sample. After synthesis, the investigation of the electro-catalytic properties of the bare (GC) and graphene-modified electrode (NB-Gr/GC) towards cymoxanil detection (CYM) was performed. Significant differences between the two electrodes were noticed. In the first case (GC) the peak current modulus was small (1.12 × 10−5 A) and appeared in the region of negative potentials (−0.9 V). In contrast, when NB-Gr was present on top of the GC electrode it promoted the transfer of electrons, leading to a large peak current increase (1.65 × 10−5 A) and a positive shift of the peak potential (−0.75 V). The NB-Gr/GC electrode was also tested for its ability to detect cymoxanil from a commercial fungicide (CURZATE MANOX) by the standard addition method, giving a recovery of 99%.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

scholarly journals Cobalt-doped bioceramic scaffolds fabricated by 3D printing show enhanced osteogenic and angiogenic properties for bone repair

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jungang Li ◽  
Chaoqian Zhao ◽  
Chun Liu ◽  
Zhenyu Wang ◽  
Zeming Ling ◽  
...  
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Bone Regeneration ◽  
Doping Concentration ◽  
Artificial Bone ◽  
Bone Defect Repair ◽  
Co Doping ◽  
Defect Repair ◽  
Co Doped

Abstract Background The bone regeneration of artificial bone grafts is still in need of a breakthrough to improve the processes of bone defect repair. Artificial bone grafts should be modified to enable angiogenesis and thus improve osteogenesis. We have previously revealed that crystalline Ca10Li(PO4)7 (CLP) possesses higher compressive strength and better biocompatibility than that of pure beta-tricalcium phosphate (β-TCP). In this work, we explored the possibility of cobalt (Co), known for mimicking hypoxia, doped into CLP to promote osteogenesis and angiogenesis. Methods We designed and manufactured porous scaffolds by doping CLP with various concentrations of Co (0, 0.1, 0.25, 0.5, and 1 mol%) and using 3D printing techniques. The crystal phase, surface morphology, compressive strength, in vitro degradation, and mineralization properties of Co-doped and -undoped CLP scaffolds were investigated. Next, we investigated the biocompatibility and effects of Co-doped and -undoped samples on osteogenic and angiogenic properties in vitro and on bone regeneration in rat cranium defects. Results With increasing Co-doping level, the compressive strength of Co-doped CLP scaffolds decreased in comparison with that of undoped CLP scaffolds, especially when the Co-doping concentration increased to 1 mol%. Co-doped CLP scaffolds possessed excellent degradation properties compared with those of undoped CLP scaffolds. The (0.1, 0.25, 0.5 mol%) Co-doped CLP scaffolds had mineralization properties similar to those of undoped CLP scaffolds, whereas the 1 mol% Co-doped CLP scaffolds shown no mineralization changes. Furthermore, compared with undoped scaffolds, Co-doped CLP scaffolds possessed excellent biocompatibility and prominent osteogenic and angiogenic properties in vitro, notably when the doping concentration was 0.25 mol%. After 8 weeks of implantation, 0.25 mol% Co-doped scaffolds had markedly enhanced bone regeneration at the defect site compared with that of the undoped scaffold. Conclusion In summary, CLP doped with 0.25 mol% Co2+ ions is a prospective method to enhance osteogenic and angiogenic properties, thus promoting bone regeneration in bone defect repair.

Sign in / Sign up

Export Citation Format

Share Document