Defect dependent inverted shift of band structure for ZnO nanoparticles

Ghose, Srabantika; Jana, Debnarayan

doi:10.1088/2053-1591/ab3b15

Cited by 10 publications

(5 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…67,68 This is due to the ZnO band edge absorption peak. 69,70 No detectable signals were observed for the silica NP mixtures.…”

Section: Resultsmentioning

confidence: 98%

Fluorine-free nanoparticle coatings on cotton fabric: comparing the UV-protective and hydrophobic capabilities of silica vs. silica-ZnO nanostructures

Liu,

Hu,

Fei

et al. 2024

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…67,68 This is due to the ZnO band edge absorption peak. 69,70 No detectable signals were observed for the silica NP mixtures.…”

Section: Resultsmentioning

confidence: 98%

Fluorine-free nanoparticle coatings on cotton fabric: comparing the UV-protective and hydrophobic capabilities of silica vs. silica-ZnO nanostructures

Liu,

Hu,

Fei

et al. 2024

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…42 The c/a ratio also provides information about the vacancies in materials. 44,45 The c/a ratio of the wurtzite structure is 1.633; however, the c/a ratios of ZnO prepared using different ash water extracts are in the range of 1.601−1.603, probably due to Zn or O vacancies created during nanostructure formation. 43 The observed values are very close to the standard JCPDS data and reported results, showing that pure-phase ZnO is successfully synthesized using different ash water extracts.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, one of the decisive factors that greatly influence the optical bandgap of the sample is defect states and their concentration within the forbidden gap. 44,58 Furthermore, depending on the dislocation density, the bandgap varies. 59 The c/a ratio of the prepared samples showed a considerable deviation indicating the presence of a defect state in materials.…”

Section: Resultsmentioning

confidence: 99%

“…The energy gap appears due to the transition of electrons from the valence band (VB) to the empty conduction band (CB) of semiconductors, which is ∼3.37 eV for single-crystal ZnO. Therefore, one of the decisive factors that greatly influence the optical bandgap of the sample is defect states and their concentration within the forbidden gap. , Furthermore, depending on the dislocation density, the bandgap varies . The c / a ratio of the prepared samples showed a considerable deviation indicating the presence of a defect state in materials …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Nanostructural Design of ZnO Using an Agro-Waste Extract for a Sustainable Process and Its Photocatalytic Activity

Wary,

Narzary,

Brahma

et al. 2023

ACS Appl. Bio Mater.

View full text Add to dashboard Cite

The use of agro-waste extracts (AWEs) as a sustainable medium for developing cost-effective and ecologically friendly nanomaterials has piqued the interest of current researchers. Herein, waste extracts from papaya barks, banana peels, thumba plants, and snail shells were used for synthesizing ZnO nanostructures via a hydrothermal method, followed by calcination at 400 °C. The crystallinity and pure wurtzite phase formation of ZnO nanostructures were confirmed via X-ray diffraction. ZnO nanostructures with various morphologies such as tight sheet-like, spherical, porous sheet-like, and bracket-shaped, comprising small interconnected particles with a highly catalytically active exposed (0001) facet, were observed via field emission scanning electron microscopy and transmission electron microscopy. The formation mechanism of the various morphologies of the ZnO nanostructures was proposed. Ultraviolet–visible spectra showed different absorption band edges of ZnO nanostructures with a bandgap in the range of 3.17–3.27 eV. Photoluminescence studies showed the presence of various defect states such as oxygen and zinc vacancies and oxygen and zinc interstitials on ZnO nanostructures, which are usually observed in traditionally prepared ZnO. The photocatalytic activity of ZnO nanostructures was evaluated under direct sunlight using rhodamine B (RhB) and Congo red (CR) dyes as probe pollutants. Furthermore, prepared ZnO nanostructures could potentially adsorb anionic dyes (e.g., CR) in the absence of light. Superoxide and hydroxide radicals played a vital role in the photocatalytic activity of ZnO. The photocatalyst could be reused for up to three cycles, indicating its stability. Therefore, this study reports the diverse use of AWEs as cost-effective media for nanomaterial synthesis.

show abstract

“…With 1% Mn-ZnO, E g decreased to 3.4 eV. The drop in E g can be related to an increase in particle size and the concentration of oxygen vacancies on the ZnO surface [ 56 ]. Localized defect states within the band gap are created by the oxygen vacancy and the related disorder, resulting in a redshift of the band gap [ 57 ].…”

Section: Resultsmentioning

confidence: 99%

Photovoltaic Properties of ZnO Films Co-Doped with Mn and La to Enhance Solar Cell Efficiency

et al. 2022

View full text Add to dashboard Cite

In the present investigation, ZnO films co-doped with Mn and La were synthesized by the sol–gel technique. XRD analysis revealed that ZnO had a hexagonal structure. Mixed hexagonal and cubic phases appeared in ZnO containing Mn (1%) and La (1.5%). The grain size, d-spacing, unit cell, lattice parameters, atomic packing fraction, volume, strain, crystallinity, and bond length of co-doped ZnO films were determined as a function of doped ion contents. Through UV analysis, it was found that pristine ZnO had Eg = 3.5 eV, and it decreased when increasing the doping concentration, reaching the minimum value for the sample with 1% Mn and 1% La. The optical parameters of the films, such as absorption, transmittance, dielectric constants, and refractive index, were also analyzed. DSSCs were fabricated using the prepared ZnO films. For pure ZnO film, the values were: efficiency = 0.69%, current density = 2.5 mAcm−2, and open-circuit voltage = 0.56 V. When ZnO was co-doped with Mn and La, the efficiency increased significantly. DSSCs with a ZnO photoanode co-doped with 1% Mn and 1% La exhibited maximum values of Jsc = 4.28 mAcm−2, Voc = 0.6 V, and efficiency = 1.89%, which is 174% better than pristine ZnO-based DSSCs. This material is good for the electrode of perovskite solar cells.

show abstract

Defect dependent inverted shift of band structure for ZnO nanoparticles

Cited by 10 publications

References 28 publications

Fluorine-free nanoparticle coatings on cotton fabric: comparing the UV-protective and hydrophobic capabilities of silica vs. silica-ZnO nanostructures

Fluorine-free nanoparticle coatings on cotton fabric: comparing the UV-protective and hydrophobic capabilities of silica vs. silica-ZnO nanostructures

Nanostructural Design of ZnO Using an Agro-Waste Extract for a Sustainable Process and Its Photocatalytic Activity

Photovoltaic Properties of ZnO Films Co-Doped with Mn and La to Enhance Solar Cell Efficiency

Contact Info

Product

Resources

About