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.

Growth of Low Resistivity p-Type 4H-SiC Crystals by Sublimation with Using Aluminum and Nitrogen Co-Doping

2016 ◽  
Vol 858 ◽  
pp. 77-80 ◽  
Author(s):  
Kazuma Eto ◽  
Hiromasa Suo ◽  
Tomohisa Kato ◽  
Hajime Okumura
Keyword(s):  
Raman Spectroscopy ◽  
Bulk Crystals ◽  
High Concentration ◽  
Al Doping ◽  
Low Resistivity ◽  
Co Doping ◽  
Sublimation Method ◽  
P Type ◽  
Sublimation Growth ◽  
Doping Condition

Low resistivity p-type SiC bulk crystals were grown by the sublimation method with using aluminum and nitrogen co-doping. In the sublimation growth of 4H-SiC, to obtain low-resistive p-type crystals are not easy because of the instability of 4H-SiC polytype with highly Al-doping. We have grown < 90 mΩcm p-type 4H-SiC bulk crystals with the co-doping condition. The results of SIMS and Raman spectroscopy show that high concentration of nitrogen co-doping could be effective to the stabilization of 4H polytype with p-type SiC growth.

scholarly journals Photo-activity and low resistivity in N/Nb Co-doped TiO2 thin films by combinatorial AACVD

2016 ◽  
Vol 4 (2) ◽  
pp. 407-415 ◽  
Author(s):  
Nicholas P. Chadwick ◽  
Emily N. K. Glover ◽  
Sanjayan Sathasivam ◽  
Sulaiman N. Basahel ◽  
Shaeel A. Althabaiti ◽  
...  
Keyword(s):  
Thin Films ◽  
Functional Properties ◽  
Tio2 Thin Films ◽  
Doped Tio2 ◽  
Low Resistivity ◽  
Co Doping ◽  
Co Doped

Combinatorial AACVD has achieved the production of various niobium/nitrogen co-doped TiO2 materials in a single film. The co-doping concentrations have been correlated with functional properties.

Reducing Stacking Faults in Highly Doped N-Type 4H-SiC Crystal

2011 ◽  
Vol 679-680 ◽  
pp. 8-11 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Tomohisa Kato ◽  
Sachiko Ito ◽  
Jun Kojima ◽  
Fusao Hirose ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Stacking Fault ◽  
Suppression Effect ◽  
Co Doping ◽  
N Concentration

We investigated a way of reducing the stacking fault (SF) density on a highly nitrogen (N) doped 4H-SiC crystal. SFs were generated at highly N doped crystal exceeding 4 x 1019 cm-3 and the density was increased with increasing N concentration. We found that Al co-doping had the potential to suppress this SF generation and was effective up to an N concentration of about 1 x 1021cm-3. This effect depended strongly on the Al concentration. We discussed the reason for the SF suppression effect of Al co-doping.

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...

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.

Transport mechanisms in Co-doped ZnO (ZCO) and H-irradiated ZCO polycrystalline thin films

2021 ◽  
Vol 23 (3) ◽  
pp. 2368-2376
Author(s):  
A. Di Trolio ◽  
A. Amore Bonapasta ◽  
C. Barone ◽  
A. Leo ◽  
G. Carapella ◽  
...  
Keyword(s):  
Thin Films ◽  
Opposite Effect ◽  
Transport Mechanisms ◽  
Co Doping ◽  
Polycrystalline Thin Films ◽  
Doped Zno ◽  
Co Doped

Co doping increases the ZnO resistivity (ρ) at high T (HT), whereas it has an opposite effect at low T (LT). H balances the Co effects by neutralizing the ρ increase at HT and strengthening its decrease at LT.

Synergistic Effect of Eu3+ and Sm3+ Co-Doping on Photocatalytic Activity of TiO2 Nanoparticles

2011 ◽  
Vol 197-198 ◽  
pp. 891-894 ◽  
Author(s):  
Cheng Zhi Jiang ◽  
Xu Dong Lu
Keyword(s):  
Photocatalytic Activity ◽  
Synergistic Effect ◽  
Sol Gel ◽  
Blue Shift ◽  
Nano Particles ◽  
Absorption Profile ◽  
Co Doping ◽  
The Matrix ◽  
Co Doped ◽  
The Eu

Pure TiO2, Eu3+and Sm3+co-doping TiO2composite nanoparticles have been prepared by sol-gel method and characterized by the techniques such as XRD, SEM and DRS. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The matrix distortion of TiO2nano-particles increases after co-doping of Eu3+and Sm3+and a blue-shift of the absorption profile are clearly observed. The results show that co-doping of Eu3+and Sm3+inhibits the phase transformation of TiO2from anatase to rutile, decreases the diameter of TiO2nano-particles and significantly enhance the photocatalytic activity of TiO2. The Eu3+and Sm3+co-doped into TiO2nano-particles exert a synergistic effect on their photocatalytic activity.

Effect of cobalt doping on microstructures and dielectric properties of ZnO

2019 ◽  
Vol 97 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Ye Zhao ◽  
Fan Tong ◽  
Mao Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Co Doping ◽  
In Doping ◽  
Zno Powders ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Pure and cobalt-doped ZnO nanoparticles (2.5, 5, 7.5, and 10 atom % Co) are synthesized by sol–gel method. The as-synthesized nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) analysis. The nanoparticles of 0, 2.5, and 5 atom % Co-doped ZnO exhibited hexagonal wurtzite structure and have no other phases. Moreover, the (101) diffraction peaks position of Co-doped ZnO shift toward a smaller value of diffraction angle compared with pure ZnO powders. The results confirm that Co ions were well incorporated into ZnO crystal lattice. Simultaneously, Co doping also inhibited the growth of particles, and the crystallite size decreased from 43.11 nm to 36.63 nm with the increase in doping concentration from 0 to 10 atom %. The values of the optical band gap of all Co-doped ZnO nanoparticles gradually decreased from 3.09 eV to 2.66 eV with increasing Co content. Particular, the dielectric constant of all Co-doped ZnO ceramics gradually increased from 1.62 × 103 to 20.52 × 103, and the dielectric loss decreased from 2.36 to 1.28 when Co content increased from 0 to 10 atom %.

scholarly journals Synthesis and Characterization of Sn/Ni Single Doped and Co–Doped Anatase/Rutile Mixed–Crystal Nanomaterials and Their Photocatalytic Performance under UV–Visible Light

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1341
Author(s):  
Qin Qin ◽  
Juan Wang ◽  
Yangwen Xia ◽  
Daixiong Yang ◽  
Qin Zhou ◽  
...  
Keyword(s):  
Visible Light ◽  
Mixed Crystal ◽  
Inhibitory Effect ◽  
Reaction Rate Constant ◽  
Charge Recombination ◽  
Pure Tio2 ◽  
Ni Doping ◽  
Sn Doping ◽  
Co Doping ◽  
Co Doped

Pure and Sn/Ni co–doped TiO2 nanomaterials with anatase/rutile mixed crystal were prepared and characterized. The results show that pure TiO2 is a mixed crystal structure composed of a large amount of anatase and a small amount of rutile. Sn doping promotes the phase transformation from anatase to rutile, while Ni doping inhibits the transformation. Both single doping and co–doping are beneficial to the inhibition of photoinduced charge recombination. Sn doping shows the best inhibitory effect on photogenerated charge recombination, and increases the utilization of visible light, displaying the highest photocatalytic activity. The decolorization degree of methylene blue (MB) by Sn–TiO2 is 79.5% after 150 min. The reaction rate constant of Sn–TiO2 is 0.01022 min−1, which is 5.6 times higher than pure TiO2 (0.00181 min–1).

Sign in / Sign up

Export Citation Format

Share Document