Charge compensation assisted enhancement of photoluminescence in combustion derived Li+ co-doped cubic ZrO2:Eu3+ nanophosphors

2016 ◽  
Vol 18 (42) ◽  
pp. 29447-29457 ◽  
Author(s):  
D. Prakashbabu ◽  
H. B. Ramalingam ◽  
R. Hari Krishna ◽  
B. M. Nagabhushana ◽  
R. Chandramohan ◽  
...  
Keyword(s):  
Charge Compensation ◽  
Charge Imbalance ◽  
Co Doped

Doping of a Eu3+ for a tetravalent ion (Zr4+ here) creates charge imbalance in the system that results in vacancies in the ZrO2 lattice. Here, charge compensation is achieved by replacement of one Zr4+ ion by a Eu3+ and a Li+.

Tunable Carbon Surface from Mono- to Multi-Metallic Single Atoms

2020 ◽  
Author(s):  
Weihong Lai ◽  
Heng Wang ◽  
Quan jiang ◽  
Zichao Yan ◽  
Hanwen Liu ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Structural Evolution ◽  
Charge Compensation ◽  
Catalytic Reactions ◽  
Single Atom ◽  
Carbon Surface ◽  
Hydrogen Electrode ◽  
Single Atoms ◽  
Mass Activity ◽  
Co Doped

<p>Herein, we develop a non-selective charge compensation strategy to prepare multi-single-atom doped carbon (MSAC) in which a sodium p-toluenesulfonate (PTS-Na) doped polypyrrole (S-PPy) polymer is designed to anchor discretionary mixtures of multiple metal cations, including iron (Fe<sup>3+</sup>), cobalt (Co<sup>3+</sup>), ruthenium (Ru<sup>3+</sup>), palladium (Pd<sup>2+</sup>), indium (In<sup>3+</sup>), iridium (Ir<sup>2+</sup>), and platinum (Pt<sup>2+</sup>) . As illustrated in Figure 1, the carbon surface can be tuned with different level of compositional complexities, including unary Pt<sub>1</sub>@NC, binary (MSAC-2, (PtFe)<sub>1</sub>@NC), ternary (MSAC-3, (PtFeIr)<sub>1</sub>@NC), quaternary (MSAC-4, (PtFeIrRu)<sub>1</sub>@NC), quinary (MSAC-5, (PtFeIrRuCo)<sub>1</sub>@NC), senary (MSAC-6, (PtFeIrRuCoPd)<sub>1</sub>@NC), and septenary (MSAC-7, (PtFeIrRuCoPdIn)<sub>1</sub>@NC) samples. The structural evolution of carbon surface dictates the activities of both ORR and HER. The senary MSAC-6 achieves the ORR mass activity of 18.1 A·mg<sub>metal</sub><sup>-1</sup> at 0.9 V (Vs reversible hydrogen electrode (RHE)) over 30K cycles, which is 164 times higher than that of commercial Pt/C. The quaternary MSAC-4 presented a comparable HER catalytic capability with that of Pt/C. These results indicate that the highly complexed carbon surface can enhance its ability over general electrochemical catalytic reactions. The mechanisms regarding of the ORR and HER activities of the alternated carbon surface are also theoretically and experimentally investigated in this work, showing that the synergistic effects amongst the co-doped atoms can activate or inactivate certain single-atom sites.</p>

Giant dielectric response and charge compensation of Li- and Co-doped NiO ceramics

2012 ◽  
Vol 177 (9) ◽  
pp. 673-677 ◽  
Author(s):  
Yunhua Li ◽  
Liang Fang ◽  
Laijun Liu ◽  
Yanming Huang ◽  
Changzheng Hu
Keyword(s):  
Dielectric Response ◽  
Charge Compensation ◽  
Giant Dielectric ◽  
Co Doped

Charge compensation in RE3+ (RE = Eu, Gd) and M+ (M = Li, Na, K) co-doped alkaline earth nanofluorides obtained by microwave reaction with reactive ionic liquids leading to improved optical properties

2014 ◽  
Vol 2 (44) ◽  
pp. 9439-9450 ◽  
Author(s):  
C. Lorbeer ◽  
F. Behrends ◽  
J. Cybinska ◽  
H. Eckert ◽  
A.-V. Mudring
Keyword(s):  
Optical Properties ◽  
Ionic Liquids ◽  
Quantum Yield ◽  
Alkaline Earth ◽  
Charge Compensation ◽  
Luminescent Material ◽  
Microwave Reaction ◽  
Co Doped

Careful charge compensation in doubly doped alkaline earth nanofluorides enables a luminescent material with 199% quantum yield.

Photoluminescence Charateristics of SrTiO3:Pr3+,Ga3+ Single Crystal

2000 ◽  
Vol 621 ◽  
Author(s):  
Jaedong Byun ◽  
Yongjei Lee ◽  
Boyun Jang ◽  
Youngmoon Yu ◽  
Sunyoun Ryou ◽  
...  
Keyword(s):  
Emission Band ◽  
Charge Compensation ◽  
Floating Zone ◽  
Zone Method ◽  
Floating Zone Method ◽  
Co Doping ◽  
Hole Trapping ◽  
Trapping Effect ◽  
Co Doped ◽  
Considerable Enhancement

ABSTRACTSrTiO3 crystals containing varying concentrations of Pr and Ga were grown by a standard floating zone method and their photoluminescence characteristics were investigated. It was found that only a small fraction of Pr ions added are incorporated in the lattice. When the Ga ions are co-doped, the solubility of Pr ions is increased considerably. Comparing the ionic sizes of the host and dopants, it seems that the increase of solubility of Pr by Ga co-doping is due to charge compensation achieved by the additional Ga3+. The addition of Ga in Pr - activated SrTiO3 resulted also in a considerable enhancement of Pr3+ emission band at 615 nm. This result is attributed to the hole trapping effect of Ga3+ ions.

Preparation and Up-Conversion Luminescence of Yb3+ and Er3+ Co-Doped BaF2 Phosphor

2011 ◽  
Vol 287-290 ◽  
pp. 490-493
Author(s):  
Li Qun Cheng ◽  
Guang Cheng ◽  
Rui Dong ◽  
Xi Yan Zhang
Keyword(s):  
High Temperature ◽  
Luminescence Intensity ◽  
Emission Intensity ◽  
Charge Compensation ◽  
Solid Reaction ◽  
Reaction Method ◽  
Optimal Ratio ◽  
Method Effects ◽  
Co Doped

Yb3+and Er3+co-doped BaF2phosphors were prepared by high temperature solid reaction method. Effects of mol content ratios of Yb3+ion to Er3+ion (CYb3+∶CEr3+) and charge compensation agent Na2SiF6 contents on the up-conversion luminescence of the samples were studied. The XRD and PL were carried out to investigate the phases and the up-conversion luminescence. Three up-conversion emissions were observed with peaks at 460nm, 548nm and 660nm respectively. The up-conversion luminescence intensity increases firstly, and then decreases with increasing CYb3+∶CEr3+ and the optimal ratio was found to be at 12:2 with fixed Er3+contents 2mol%. The up-conversion emission intensity was enhanced by introducing Na2SiF6 as the charge compensation agents and its optimal content was found to be 2mol%.

Facile hydrothermal synthesis and pulsed laser deposition of Ca0.5Y1−x(WO4)2:xEu3+ phosphors: investigations on the luminescence, Judd–Ofelt analysis and charge compensation mechanism

2017 ◽  
Vol 41 (2) ◽  
pp. 493-502 ◽  
Author(s):  
Venkatakrishnan Mahalingam ◽  
Jagannathan Thirumalai
Keyword(s):  
Thin Film ◽  
Hydrothermal Synthesis ◽  
Pulsed Laser ◽  
Emission Spectra ◽  
Charge Compensation ◽  
Laser Deposition ◽  
Alkali Metal Ions ◽  
Compensation Mechanism ◽  
Pl Emission ◽  
Co Doped

PL emission spectra of Ca0.5Y1−x(WO4)2:xEu3+ for powder and thin film phosphors, and PL spectra of Ca0.5Y1−x(WO4)2:xEu3+ co-doped with alkali metal ions.

scholarly journals Tunable Carbon Surface from Mono- to Multi-Metallic Single Atoms

2020 ◽  
Author(s):  
Weihong Lai ◽  
Heng Wang ◽  
Quan jiang ◽  
Zichao Yan ◽  
Hanwen Liu ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Structural Evolution ◽  
Charge Compensation ◽  
Catalytic Reactions ◽  
Single Atom ◽  
Carbon Surface ◽  
Hydrogen Electrode ◽  
Single Atoms ◽  
Mass Activity ◽  
Co Doped

<p>Herein, we develop a non-selective charge compensation strategy to prepare multi-single-atom doped carbon (MSAC) in which a sodium p-toluenesulfonate (PTS-Na) doped polypyrrole (S-PPy) polymer is designed to anchor discretionary mixtures of multiple metal cations, including iron (Fe<sup>3+</sup>), cobalt (Co<sup>3+</sup>), ruthenium (Ru<sup>3+</sup>), palladium (Pd<sup>2+</sup>), indium (In<sup>3+</sup>), iridium (Ir<sup>2+</sup>), and platinum (Pt<sup>2+</sup>) . As illustrated in Figure 1, the carbon surface can be tuned with different level of compositional complexities, including unary Pt<sub>1</sub>@NC, binary (MSAC-2, (PtFe)<sub>1</sub>@NC), ternary (MSAC-3, (PtFeIr)<sub>1</sub>@NC), quaternary (MSAC-4, (PtFeIrRu)<sub>1</sub>@NC), quinary (MSAC-5, (PtFeIrRuCo)<sub>1</sub>@NC), senary (MSAC-6, (PtFeIrRuCoPd)<sub>1</sub>@NC), and septenary (MSAC-7, (PtFeIrRuCoPdIn)<sub>1</sub>@NC) samples. The structural evolution of carbon surface dictates the activities of both ORR and HER. The senary MSAC-6 achieves the ORR mass activity of 18.1 A·mg<sub>metal</sub><sup>-1</sup> at 0.9 V (Vs reversible hydrogen electrode (RHE)) over 30K cycles, which is 164 times higher than that of commercial Pt/C. The quaternary MSAC-4 presented a comparable HER catalytic capability with that of Pt/C. These results indicate that the highly complexed carbon surface can enhance its ability over general electrochemical catalytic reactions. The mechanisms regarding of the ORR and HER activities of the alternated carbon surface are also theoretically and experimentally investigated in this work, showing that the synergistic effects amongst the co-doped atoms can activate or inactivate certain single-atom sites.</p>

Tuning the near-gap electronic structure of Cu2O by anion–cation co-doping for enhanced solar energy conversion

2017 ◽  
Vol 31 (01) ◽  
pp. 1650429 ◽  
Author(s):  
Yuan Si ◽  
Hao-Ming Yang ◽  
Hong-Yu Wu ◽  
Wei-Qing Huang ◽  
Ke Yang ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Electronic Properties ◽  
Charge Compensation ◽  
First Principles Calculations ◽  
Electron Hole ◽  
Co Doping ◽  
Critical Elements ◽  
Specific Performance ◽  
Co Doped

Doping is an effective strategy to tune the electronic properties of semiconductors, but some side effects caused by mono-doping degrade the specific performance of matrixes. As a model system to minimize photoproduced electron-hole pairs recombination by anion–cation co-doping, we investigate the electronic structures and optical properties of (Fe[Formula: see text]+[Formula: see text]N) co-doped Cu2O using the first-principles calculations. Compared to the case of mono-doping, the Fe[Formula: see text]N[Formula: see text] (a Fe (N) atom substituting a Cu (O) atom) co-doping reduces the energy cost of doping as a consequence of the charge compensation between the iron and nitrogen impurities, which eliminates the isolated levels (induced by mono-dopant) in the band gap. Interestingly, it is found that the contributions of different host atoms (Cu and O) away from anion (N) and cation (Fe) dopants to the variation of near band gap electronic structure of the co-doped Cu2O are different. Moreover, co-doping reduces the band gap and increases the visible-light absorption of Cu2O. Both band gap reduction and low recombination rate are critical elements for efficient light-to-current conversion in co-doped semiconductor photocatalysts. These findings raise the prospect of using co-doped Cu2O with specifically engineered electronic properties in a variety of solar applications.

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