Tuning violet to green emission in luminomagnetic Dy,Er co-doped ZnO nanoparticles

“…All the samples showed high reflection in visible region, confirming a small absorption of visible light by all samples. Co-doping was seen to enhance the percentage of visible light reflectance, which has also been reported previously[56,57]. The bandgap was calculated from the reflectance using the Kubela-Munk function:( ) = (1 − ) 2 /2(6)Where ( ) the Kubela-Munk is function and represents the reflectance [58, 59], is found from the y axis of the plot between reflectance and wavelength Fig.…”

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confidence: 53%

Photocatalytic and Photoluminescence Studies of La, Ce and Dy Co-Doped ZnO Nanoflowers

Irtiqa

Rahman

2021

Preprint

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In the present work, ZnO nanoparticles were doped with varying concentration of Lanthanum (La), Cerium (Ce) and Dysprosium (Dy) using a simple and cost effective co-precipitation approach at low temperatures. The resulting powders were calcined at 500 °C for 1 hour using a muffle furnace, to produce La, Ce, Dy co-doped ZnO nanoparticles with varying stoichiometry viz. Zn0.97La0.01Ce0.01Dy0.01O, Zn0.94La0.02Ce0.02Dy0.02O, Zn0.91La0.03Ce0.03Dy0.03O, Zn0.88La0.04Ce0.04 Dy0.04O and Zn0.85La0.05Ce0.05Dy0.05O. This is a simple approach for doping and doesn’t require and complex equipment, harmful chemical or sophisticated machinery. The synthesized powders were characterized using X-Ray diffraction (XRD) and Scanning electron microscopy (SEM) for studying the structure, purity, and grain morphology. The average particle size was calculated using XRD and was found to be 35 nm, it also indicated a hexagonal wurtizite structure with no secondary peaks. A change in morphology from nanorods to nanoflowers was observed as the concentration of dopants increased. Photoluminescence (PL) spectra indicated a red shift in the absorption edge towards the visible region of solar spectrum and this was further confirmed by Diffuse Reflectance Spectra (DRS). The photocatalytic properties of undoped and La, Ce, Dy co-doped ZnO nanoparticles were observed by examining the photodegradation of Rhodamine B dye under UV irradiation. Elimination of dye color indicated the total degradation of organic molecule. The results revealed that ZnO photocatalyst with La, Ce, Dy co-doping concentration Zn0.85La0.05Ce0.05Dy0.05O exhibited the best photocatalytic performance (95%) as compared to undoped ZnO. The improved photocatalytic performance can be attributed to the increased surface oxygen vacancies and adsorption capacity. Delay in recombination of charge carriers due to creation trap states in the bandgap of ZnO further improves the photocatalytic performance of doped samples.

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“… 11 − 13 Among these, zinc oxide (ZnO) semiconductors are widely investigated nanomaterials due to their large exciton binding energy of nearly ∼60 meV and direct optical bandgap energy (∼3.37 eV) at 300 K. 11 , 14 − 16 As a result of their efficient optical properties, ZnO nanostructures have become extremely appropriate host semiconductors; codoping of rare-earth ions is the most effective approach to enhance their structural, morphological, bandgap energy, and optical properties. 17 , 18 Many authors have also reported that ZnO thin films with different dopants, such as Ga, In, F, Al, Ca, modified the electrical conductivity and optical transparency of nanostructures for optoelectronic device applications. 19 − 22 In the present epoch, numerous efforts have been made by physicists and researchers toward the fabrication of ZnO nanomaterials that are simple, low cost, easy to synthesize, efficient, and suitable for large-scale production for potential applications.…”

Section: Introductionmentioning

confidence: 99%

“…Different metal-doped ZnO tetrapods with bismuth and tin oxide hybrid nanostructures such as ZnO–Bi 2 O 3 and ZnO–Zn 2 SnO 4 show good performance in humidity and gas-sensing applications . Compound semiconductors having a wide optical band gap, such as MoS 2 , ZnS, CdS, SnO 2 , TiO 2 , ZnO etc., with different nanostructures have attracted considerable attention from the scientific community due to their unique characteristic properties and prevalent applications in nanoscale devices. − Among these, zinc oxide (ZnO) semiconductors are widely investigated nanomaterials due to their large exciton binding energy of nearly ∼60 meV and direct optical bandgap energy (∼3.37 eV) at 300 K. ,− As a result of their efficient optical properties, ZnO nanostructures have become extremely appropriate host semiconductors; codoping of rare-earth ions is the most effective approach to enhance their structural, morphological, bandgap energy, and optical properties. , Many authors have also reported that ZnO thin films with different dopants, such as Ga, In, F, Al, Ca, modified the electrical conductivity and optical transparency of nanostructures for optoelectronic device applications. − In the present epoch, numerous efforts have been made by physicists and researchers toward the fabrication of ZnO nanomaterials that are simple, low cost, easy to synthesize, efficient, and suitable for large-scale production for potential applications. Therefore, several techniques have been employed to fabricate ZnO nanomaterials, such as the sol–gel method, solid-state reactions, coprecipitation, hydrothermal methods, pulse laser deposition, magnetic sputtering, electrospinning, electron gun evaporation, spray pyrolysis technique, etc. − The abovementioned techniques are very expensive and involve high temperatures to improve the crystalline quality of the films.…”

Section: Introductionmentioning

confidence: 99%

Environmentally Benign Structural, Topographic, and Sensing Properties of Pure and Al-Doped ZnO Thin Films

Dubey¹,

Zaidi

Awasthi

2022

ACS Omega

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In the present research work, Zn 1– x Al x O thin films with varying proportions of Al ( x = 0.00, 0.01, 0.02, and 0.03) are prepared by a chemical sol–gel spin-coating technique. The crystal structural, morphological, and humidity-sensing properties of the synthesized Zn 1– x Al x O thin films, with varying concentrations of Al ( x = 0.00, 0.01, 0.02, and 0.03), were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM); a special humidity-controlled chamber was designed for the humidity-sensing studies. In structural and phase analyses, XRD patterns of Zn 1– x Al x O thin films show a hexagonal wurtzite crystal structure. The average crystallite sizes of Zn 1– x Al x O thin films were calculated and found to be ∼18.00, 22.50, 26.30, and 29.70 nm using the X-ray diffraction (XRD) pattern. The surface morphology of Zn 1– x Al x O Al ( x = 0.00, 0.01, 0.02, and 0.03) thin films obtained from AFM micrographs analysis indicates the modification of the spherical grains into nanorods, which were distributed throughout the surface of the films. The SEM image of 3 wt % Al-doped ZnO nanomaterials also shows that spherical nanoparticles changed to nanorod-like structures with a high packing density. Furthermore, increasing the Al-doping concentration from 0 to 3 wt % in ZnO NPs shows lower hysteresis loss, less aging effect, and good sensitivity in the range of 9.8–16.5 MΩ/%RH. The sensitivity of the sensing materials increased with increasing Al-doping concentration, which is very useful for humidity sensors.

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Tuning violet to green emission in luminomagnetic Dy,Er co-doped ZnO nanoparticles

Cited by 29 publications

References 37 publications

Photocatalytic and Photoluminescence Studies of La, Ce, and Dy Co-doped ZnO Nanoflowers

Photocatalytic and Photoluminescence Studies of La, Ce, and Dy Co-doped ZnO Nanoflowers

Photocatalytic and Photoluminescence Studies of La, Ce and Dy Co-Doped ZnO Nanoflowers

Environmentally Benign Structural, Topographic, and Sensing Properties of Pure and Al-Doped ZnO Thin Films

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