Investigations on structural, optical and second harmonic generation in solvothermally synthesized pure and Cr-doped ZnO nanoparticles

Abstract

At the forefront of the current scientific revolution of nanoscience nanocrystals (NCs), crystalline particles grown in liquid media, stand out over other classes of inorganic nanomaterials due to the high degree of control with which their crystal structure, size, shape, and surface functionalities can be engineered in the synthesis stage and to the versatility with which they can be processed and implemented into a large spectrum of devices and processes. Doped semiconductor nanostructures can yield both high luminescence efficiencies and lifetime shortening at the same time. In the present manuscript pure and Cr-doped ZnO nanoparticles were successfully synthesized from the solution phase chemistry and investigated with respect to their structural and optical properties. The resulting powder consisting of nanocrystalline particles were characterized by X-ray diffraction (XRD), UV-Visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray analysis (EDX) techniques. A UV emission peak was observed from the exciton transition at 380 nm in the room temperature photo luminescent (PL) spectra. The blue emission band was assigned to the Zn interstitial and vacancy level transition. Even though Cr ions are known to act as an efficient non-radiative loss centre for near band gap emission (NBE), a pronounced NBE is obtained at room temperature even for a nominal Cr concentration of 8 at. %. XRD data analysis shows that the chromium dopant atoms are incorporated into the wurtzite host lattice. The grain size decreases with increasing dopant concentration. The lattice constants extracted by the Rietveld method from XRD data vary slightly with doping concentration.

Optical enhancement of Au doped ZrO2 thin films by sol–gel dip coating method

“…This restricts the contact between ZrO 2 particles with each other causing the inhibition in particle growth. The kinetics of this process is influenced by the dopant atoms, since the mobility of Au particles gets agglomerated in the grain boundaries due to impurity drag [9].…”

“…It is due to the intentional defects generated by doping ions, which may have a profound effect on the electronic and optical properties of the materials. [4][5][6][7][8] Further when the noble metals are doped with wide band gap semiconductor (ZrO 2 ) it can create new opportunities for plasmonic manipulation of light because of the plasmon resonance frequency of noble metals [9,10]. The presence of noble metals such as Au and Ag nanoparticles (NPs) in the ZrO 2 matrix, cause strong light absorption band in the visible region known as Localized surface plasmon resonance (LSPR).…”

Sonochemical assisted hydrothermal synthesis of ZnO: Cr nanoparticles loaded activated carbon for simultaneous ultrasound-assisted adsorption of ternary toxic organic dye: Derivative spectrophotometric, optimization, kinetic and isotherm study

“…Then, 2 g activated carbon was dispersed via ultrasound in 200 mL ethanol for 1.0 h (in a volumetric flask) and the same condition. 0.2 g ZnO-Cr-NP was adding to mixture, and subsequently was sonicated for 20 h at 50 °C [30,31]. The obtained products as ZnO-Cr-NP-AC were filtrated, washed with distilled water and ethanol and dried in oven at 80 °C.…”

Effect of the Growth Parameters on Nonlinear Optical Properties of Al‐Doped ZnO Nano Films

“…7 The optical properties of ZnO nano thin films have attracted wide attention by doping Al, In, Al, Ag, Mg, and other elements. [8][9][10][11][12] The nano thin films have been widely used in micro/nano optical photon devices due to its excellent feature on nonlinear optics (NLO). Therefore, it is very significant to study the optical properties of ZnO films under different Al doping density and growth parameters.…”

“…The grain size of the films decreased by Li doping and increased by Al doping. [10][11][12][13][14] The microstructure and optical excitonic prosperities of ZnO films were investigated. [15][16][17] The Maxwell-Garnett 18,19 theory as one of the macroscopic mixing theories has effectively applied in predicting the approximate would be dielectric properties of the final mixtures without having to deal with the microscopic fields in an in situ manner.…”