Oxygen induced strained ZnO nanoparticles: an investigation of Raman scattering and visible photoluminescence

Abstract

Raman and photoluminescence measurements results reveal a positive Poisson ratio in strained ZnO nanoparticles, signaling the short-range electron–phonon coupling effect and an energy red-shift in the PL spectrum.

Role of cobalt cations in short range antiferromagnetic Co3O4 nanoparticles: a thermal treatment approach to affecting phonon and magnetic properties

“…The clustering makes an evaluation of the size distribution possible. A similar behavior of nanoparticle agglomeration has also been reported from NiO 21 , ZnO 22 nanoparticles, and NiO nanowalls 23 . However, the samples annealed at 800 °C (Fig.…”

Strong Deep-Level-Emission Photoluminescence in NiO Nanoparticles

“…The wide band gap of metal oxide semiconductors has become an attractive topic from both a fundamental and a technological point of view [ 1 ]. Particularly at the nanoscale, varied and improved properties of metal oxides originate from a large surface to volume ratio of atoms, spatial confinement, reduced dimensions, lattice imperfections, and point defects (such as cation or oxygen ion vacancies) [ 2 ]. Most of the metal oxide semiconductors are limited to the harmful and expensive UV region (1.24 to 3.26 eV).…”

Phonon Confinement Induced Non-Concomitant Near-Infrared Emission along a Single ZnO Nanowire: Spatial Evolution Study of Phononic and Photonic Properties

“…Since the c -axis of the hexagonal structure is perpendicular to the scattering plane, we could not measure the lattice constant c. Based on this analysis, a schematic plot of the atomic model of a single ZnO NW is shown in Figure 1 d. The growth mechanism of the ZnO NWs is discussed in the previous report based on the above structural analysis, showing a short-circuit diffusion mechanism along the growth direction [ 26 ]. The crystal uniformity along the growth direction depending on the fabrication conditions, substrate, native defects (such as oxygen vacancies, interstitials, and antisite) or extrinsic defects can be introduced, thus leading to the control of the phonon confinement and the luminescence response in the visible regime of the ZnO nanocrystals [ 7 ].…”

“…Zinc oxide (ZnO) nanowires (NWs) are of great interest for the development of devices in various applied fields that include a direct and wideband gap, optoelectronic devices like light-emitting diodes, strong ultraviolet emissions, and solid-state lasers [ 1 , 2 , 3 , 4 , 5 ]. Recent studies on ZnO NWs have slightly shifted the focus to different aspects that include the Zn vacancy induced green luminescence [ 6 ], oxygen induced strain effect [ 7 ], and the influence of short-range correlation in phonon confinement [ 8 ]. Despite the practical importance, the current knowledge of the phonon vibration properties of ZnO nanocrystals is rather limited.…”

“…How to observe and analyze the atomic diffusion and phonon confinement in the metal-oxide nanowire, therefore, becomes important along the growth direction of a single NW, using optical measurements. A Raman mapping technique was employed to investigate the phonon and geometric properties of a single ZnO NW [ 7 , 8 ].…”