Resonant exciton-phonon coupling in ZnO nanorods at room temperature

Abstract

Vibronic and optoelectronic properties, along with detailed studies of exciton-phonon coupling at room temperature (RT) for random and aligned ZnO nanorods are reported. Excitation energy dependent Raman studies are performed for detailed analysis of multi-phonon processes in the nanorods. We report here the origin of coupling between free exciton and its associated phonon replicas, including its higher order modes, in the photoluminescence spectra at RT. Resonance of excitonic electron and resonating first order zone center LO phonon, invoked strongly by Frolich interaction, are made responsible for the observed phenomenon

Effect of Polymer Concentration on Size and Optical Properties of PbS Quantum Dots Embedded in PVA

“…where R is the quantum dot radius, E gb is the bulk band gap, E gn is the quantum-dot band gap, h is Planck's constant, m * is the effective mass of electron of the specimen. Here, the bulk band gap (E gb ) for PbS is of 0.41 eV, and electron effective mass at room temperature is of 0.175m 0 [8], where m 0 is the electron rest mass.…”

Morphological and spectroscopic studies on the vertically aligned zinc oxide nanorods grown on low and high temperature deposited seed layer

“…Overtone modes up to three orders are observed. With an increase in the order of overtone, the count is also increased which is a sign of good crystallinity [26].…”

Effect of substrate temperature on microstructural, vibrational and electrical properties of ZnO nanostructured thin films

“…At the zone-center (Γ-point of the Brillouin zone), the optical phonons have the irreducible representation Γ opt = A 1 + 2B 1 + E 1 + 2E 2 [8], whereas the E modes are doubly degenerate. The B 1 modes are silent, i.e.…”