Estimation of electron–phonon coupling and Urbach energy in group-I elements doped ZnO nanoparticles and thin films by sol–gel method

Journal Article · Sun May 15 00:00:00 EDT 2016 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2016.01.015· OSTI ID:22581531

Vettumperumal, R. ^[1]; Santoshkumar, B. ^[2]; Thangavel, R. ^[3]

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1. Department of Physics, V.V. College of Engineering, Tisaiyanvilai (India)
2. P.G. and Research department of Physics, Sri Paramakalyani College, Alwarkurichi 627412 (India)
3. Department of Applied Physics, Indian School of Mines, Dhanbad (India)

Highlights: • Comparison of group-I elements doped ZnO nanoparticles and thin films. • Calculation of electron–phonon coupling and phonon lifetime from Raman spectroscopy. • Estimation of interband states from Urbach energy. - Abstract: Group-I (Li, Na, K & Cs) elements doped ZnO nanoparticles (NPs) and thin films were prepared using sol–gel method. XRD data and TEM images confirm the absence of any other secondary phase different from wurtzite type ZnO. Spherical shapes of grains are observed from the surfaces of doped ZnO films by atomic force microscope images (AFM) and presences of dopants are confirmed from energy dispersive X-ray spectra. The Raman active E{sub 2} (high), E{sub 2} (low), E{sub 1} and A{sub 1} (LO) modes are observed from both ZnO NPs and thin films. First-order longitudinal optical (LO) phonon is found to have contributions from direct band transition and localized excitons. Electron–phonon coupling, phonon lifetime and deformation energy of ZnO are calculated based on the effect of dopants with respect to the multiple Raman LO phonon scattering. Presence of localized interbands states in doped ZnO NPs and thin films are found from the Urbach energy calculations.

• OSTI ID: 22581531
• Journal Information: Materials Research Bulletin, Vol. 77; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC FORCE MICROSCOPY
DEFORMATION
DOPED MATERIALS
ELECTRON-PHONON COUPLING
EXCITONS
NANOPARTICLES
OPTICAL PROPERTIES
RAMAN SPECTROSCOPY
SOL-GEL PROCESS
SURFACES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTRA
ZINC OXIDES