Raman analysis of longitudinal optical phonon-plasmon coupled modes of aligned ZnO nanorods

Abstract

The electronic properties of vertically aligned ZnO nanorods have been investigated using micro-Raman spectroscopy. The concentration and mobility of the charge carriers were determined via Raman line shape analysis using longitudinal-optical-phonon-plasmon coupled mode. The local laser heating and the stress effects have been considered when analyzing the Raman spectra. The mobility and carrier concentration of the aligned ZnO nanorods are 84.8 cm 2 / V s and 3.8 ϫ 10 17 cm −3 , respectively. As a comparison, the mobility and carrier concentration of the undoped bulk ZnO were also obtained from the Raman line shape analysis. The mobility of the aligned ZnO nanorods is about 20% lower than that of the undoped bulk ZnO, which can be attributed to enhanced surface scattering due to the reduction in dimension.

Observation of whispering gallery modes from hexagonal ZnO microdisks using cathodoluminescence spectroscopy

“…22 Thus, the narrow and strong E 2 high mode combined with a very weak A 1 mode confirm that the fabricated ZnO microdisks have predominantly wurtzite crystal structure.…”

Growth of ZnO Nanorod Arrays on Flexible Substrates: Effect of Precursor Solution Concentration

“…Lorentzian functions were employed to fit the Raman spectra in the region between 300 and 600 cm −1 . The observed peaks at about 438 and 586 cm −1 are assigned to be E (2) 2 (high-frequency E 2 mode) and Quasi-LO (QLO), respectively, [33][34][35]. The peak at 329 cm −1 results from the multiple phonon scattering processes [36].…”

Effect of cobalt doping on structural, thermo and photoluminescent properties of ZnO nanopowders

“…The broad blue band emission peaks are assigned to surface defects such as oxygen vacancies (V o ) and Zinc interstitials (Zn i ). The green emission origin is generally assigned to the radiative recombination of photo generated holes in the valence band with electrons in singly occupied oxygen vacancies [20,22]. The PL emission intensity is found to decrease with the increase in cobalt concentration as shown in the inset of Fig.…”

“…The A 1 (LO) and A 2 (LO) phonon modes of ZnO nanoparticles are observed at 578 and 1175 cm −1 , respectively. The peaks at 502, 681, 766, 865 and 967 cm −1 are due to multi phonon modes [19][20][21]. The detailed assignments of each mode for all the peaks are tabulated in the Table 2.…”