Is ZnO Raman active?

Is ZnO Raman active?

We have observed significant Raman shifts for these ZnO nanostructures in the typical Raman-active modes assigned to ZnO. Raman spectra of various as-grown nanostructures. The main peak E 2 (High) shows blue shift for all nanostructures in comparison with the theoretical and experimental bulk counter parts.

What is the band gap of ZnO nanoparticles?

The optical band gap value obtained for ZnO nanoparticle at pH=7.5 is 3.63 eV.

What is Nano ZnO?

Zinc oxide nanoparticles are nanoparticles of zinc oxide (ZnO) that have diameters less than 100 nanometers. The most common use of ZnO nanoparticles is in sunscreen. They are used because they effectively absorb ultraviolet light, but possess a large enough bandgap to be completely transparent to visible light.

What does a Raman spectra show?

Raman Spectroscopy is a non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphy, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material.

Is ZnO direct or indirect band gap?

Zinc oxide, an important semiconductor with a direct wide band gap and large exciton binding energy, has been used for solar cells, transparent electrodes, and blue/ultraviolet light emitting devices.

What is direct and indirect band gap?

If the k-vectors are different, the material has an “indirect gap”. The band gap is called “direct” if the crystal momentum of electrons and holes is the same in both the conduction band and the valence band; an electron can directly emit a photon. Some III-V materials are indirect bandgap as well, for example AlSb.

What is Nano zinc used for?

Zinc oxide (ZnO) nanoparticles (NP) particles are being extensively used in paints, skin lotions pigments, food, electronics appliances, biological and pharmaceutical applications and many more.

How do you make Nano ZnO?

ZnO nanoparticles were synthesized via sol gel method using Zinc acetate dehydrate (Zn(CH3COO)2. 2H2O) as a precursor and ethanol (CH2COOH) was used as solvent, Sodium hydroxide (NaOH) and distilled water were used as medium. ZnO nanoparticles were characterized by using XRD, EDX, FESEM, and nano-particles analyser.

What is the basic concept of Raman effect?

Raman effect, change in the wavelength of light that occurs when a light beam is deflected by molecules. When a beam of light traverses a dust-free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than that of the incident (incoming) beam.

How do we get Raman spectra?

It is usually necessary to separate the Raman scattered light from the Rayleigh signal and reflected laser signal in order to collect high quality Raman spectra using a laser rejection filter. Notch or long-pass optical filters are typically used for this purpose.

Is ZnO polar or nonpolar?

It is known that Zinc oxide has positive charged Zn polar surface, negative charged O polar surface, and 6 non-polar faces.

Is ZnO a semiconductor?

Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically. ZnO is a wide-band gap semiconductor of the II-VI semiconductor group. The native doping of the semiconductor due to oxygen vacancies or zinc interstitials is n-type.

What is ZnO Raman spectrum?

Zinc Oxide Raman Spectrum Zinc oxide (ZnO) is a semiconductor with a hexagonal structure. From the standpoint of research, it is an extraordinary material due to the remarkable combination of its electronic, optical, electrical, structural, and morphological properties.

Can Raman spectroscopy study the structural evolution of ZnO/Nio nanocomposite?

Since Raman scattering study is based on the inelastic scattering due to lattice phonons, the nature of the material structure and structural disorder and, can be investigated using the Raman spectroscopic techniques. In this paper, we investigated the structural evolution of ZnO/NiO nanocomposite at varying Ni concentrations.

Can Raman spectroscopy detect structural defects in sintered ZnO ceramic samples?

Thus, in this work we present a Raman spectroscopy study of two ZnO ceramic samples sintered according to the structural disorder defects; i.e., samples with low and high porosity levels. All samples were prepared by the conventional pressure-less solid-state reaction method with control on the sintering temperature program.

What is the Raman line-shape of low and high dense ZnO ceramic materials?

A detailed study of Raman line-shape of low and high dense ZnO ceramics was carried out using a Raman microprobe system with a solid-state laser source of 532 nm wavelength and 100 mW power at room temperature. The Raman activated bands for the ZnO wurtzite structure were observed in both samples.