Designing Dual Emissions via Co-doping or Physical Mixing of Individually Doped ZnO and Their Implications in Optical Thermometry

2017 ◽  
Vol 9 (19) ◽  
pp. 16305-16312 ◽  
Author(s):  
Subrata Senapati ◽  
Karuna Kar Nanda
Keyword(s):  
Co Doping ◽  
Optical Thermometry ◽  
Physical Mixing ◽  
Doped Zno ◽  
Dual Emissions

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.

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 %.

Removal of Ferrimagnetic ZnFe2O4 Impurity Phase by Li Co-Doping in Fe Doped ZnO

2021 ◽  
Vol 10 (1) ◽  
pp. 013004
Author(s):  
Md. Azaharuddin Ahmed ◽  
Sudipta Bandyopadhyay ◽  
Aritra Banerjee
Keyword(s):  
Impurity Phase ◽  
Co Doping ◽  
Doped Zno

Study on the effects of Ga-2N high co-doping and preferred orientation on the stability, bandgap and absorption spectrum of ZnO

2017 ◽  
Vol 31 (14) ◽  
pp. 1750107
Author(s):  
Qing-Yu Hou ◽  
Wen-Cai Li ◽  
Ling-Feng Qu ◽  
Chun-Wang Zhao
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Theoretical Calculations ◽  
Co Doping ◽  
Unit Cells ◽  
Neighboring Site ◽  
Doped Zno ◽  
The Stability ◽  
Formation Energies ◽  
Co Doped

Currently, the stability and visible light properties of Ga-2N co-doped ZnO systems have been studied extensively by experimental analysis and theoretical calculations. However, previous theoretical calculations arbitrarily assigned Ga- and 2N-doped sites in ZnO. In addition, the most stable and possible doping orientations of doped systems have not been fully and systematically considered. Therefore, in this paper, the electron structure and absorption spectra of the unit cells of doped and pure systems were calculated by first-principles plane-wave ultrasoft pseudopotential with the GGA[Formula: see text]U method. Calculations were performed for pure ZnO, Ga-2N supercells heavily co-doped with Zn[Formula: see text]Ga[Formula: see text]O[Formula: see text]N[Formula: see text] ([Formula: see text], [Formula: see text]) under different co-doping orientations and conditions, and the Zn[Formula: see text]GaN2O[Formula: see text] interstitial model. The results indicated that under different orientations and constant Ga-2N co-doping concentrations, the systems co-doped with Ga-N atoms vertically oriented to the [Formula: see text]-axis and with another N atom located in the nearest-neighboring site exhibited higher stability over the others, thus lowering formation energy and facilitating doping. Moreover, Ga-interstitial- and 2N-co-doped ZnO systems easily formed chemical compounds. Increasing co-doping concentration while the co-doping method remained constant decreased doped system volume and lowered formation energies. Meantime, co-doped systems were more stable and doping was facilitated. The bandgap was also narrower and red shifting of the absorption spectrum was more significant. These results agreed with previously reported experimental results. In addition, the absorption spectra of Ga-interstitial- and 2N-co-doped ZnO both blue shifted in the UV region compared with that of the pure ZnO system.

Structural and Electrical Properties of (Cu, Co) Co-Doped ZnO Thin Film

2013 ◽  
Vol 774-776 ◽  
pp. 964-967
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Electrical Properties ◽  
Sol Gel ◽  
Hall Effect Measurement ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Co Doping ◽  
Structural And Electrical Properties ◽  
Doped Zno ◽  
Cu Ions ◽  
Co Doped

Successful synthesis of Cu, Co co-doped ZnO film is obtained by sol-gel method. The structural and electrical properties of the sample were investigated. X-ray diffraction spectroscopy analyses indicate that the Co and Cu co-doping can not disturb the structure of ZnO. No additional peaks are observed in the Zn0.99Co0.01CuxO and Cu+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. By Hall-effect measurement p-type conductivity was observed for the Cu co-doped film. XPS result confirmed Cu ions are univalent in the films.

The Structural, Electrical, Magnetic Properties of (Cu, Co) Co-Doped ZnO Thin Film

2014 ◽  
Vol 556-562 ◽  
pp. 429-432
Author(s):  
Ping Cao ◽  
Yue Bai ◽  
Zhi Qu
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Sol Gel ◽  
Hall Effect Measurement ◽  
Ferromagnetic Semiconductors ◽  
Zno Thin Film ◽  
Zno Film ◽  
Co Doping ◽  
Doped Zno ◽  
Co Doped

Successful synthesis of room-temperature ferromagnetic semiconductors, (Cu, Co) co-doped ZnO film is obtained by sol-gel method. It is found that the essential ingredient in achieving room-temperature ferromagnetism is Cu co-doping. By Hall-effect measurement ap-type conductivity was observed for the Cu co-doped films, which induced the room-temperature ferromagnetism.

Effect of Co doping on the physical properties of Co-doped ZnO nanoparticles

2017 ◽  
Vol 28 (8) ◽  
pp. 5953-5961 ◽  
Author(s):  
Zohra N. Kayani ◽  
Iqra Shah ◽  
Saira Riaz ◽  
Shahzad Naseem
Keyword(s):  
Physical Properties ◽  
Zno Nanoparticles ◽  
Co Doping ◽  
Doped Zno ◽  
Co Doped

scholarly journals Electroluminescence from light-emitting devices based on erbium-doped ZnO/n-Si heterostructures: Enhancement effect of fluorine co-doping

2019 ◽  
Vol 27 (21) ◽  
pp. 30919 ◽  
Author(s):  
Jinxin Chen ◽  
Weijun Zhu ◽  
Yuhan Gao ◽  
Deren Yang ◽  
Xiangyang Ma
Keyword(s):  
Enhancement Effect ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Co Doping ◽  
Erbium Doped ◽  
Doped Zno

scholarly journals Physical Investigations of (Co, Mn) Co-Doped ZnO Nanocrystalline Films

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1507
Author(s):  
Bechir Yahmadi ◽  
Olfa Kamoun ◽  
Badriyah Alhalaili ◽  
Safia Alleg ◽  
Ruxandra Vidu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Texture Coefficient ◽  
Room Temperature Ferromagnetism ◽  
Band Gap Energy ◽  
X Ray ◽  
Co Doping ◽  
Glass Substrates ◽  
Doped Zno ◽  
Co Doped

Undoped as well as (Co, Mn) co-doped Zinc oxides have been effectively developed on glass substrates, taking advantage of the spray pyrolysis procedure. The X-ray diffraction XRD as well as X-ray photoelectron spectroscopy (XPS) measurements have recognized a pure hexagonal wurtzite form of ZnO, and no other collateral phases such as MnO2 or CoO2 have been observed as a result of doping. The calculated values of the texture coefficient (TC) were between 0.15 and 5.14, indicating a dominant orientation along the (002) plane. The crystallite size (D) varies with the (Co, Mn) contents. The dislocation density (δ) as well as the residual microstrains increased after Co and Mn doping. Furthermore, the surface morphology of the films has been affected significantly by the Co and Mn incorporation, as shown by the scanning electron microscopy (SEM) investigation. The study of the optical properties exhibits a red shift of the band gap energy (Eg) with the (Co, Mn) co-doping. The magnetic measurements have shown that the undoped and (Co, Mn) co-doped ZnO thin films displayed room-temperature ferromagnetism (RTFM).

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