Title :
Pulsed laser deposited stoichiometric ZnO thin films
Author :
Ashrafi, Almamun
Author_Institution :
Dept. of Electron. Mater. Eng., Australian Nat. Univ., Canberra, ACT
fDate :
July 28 2008-Aug. 1 2008
Abstract :
Room temperature free-exciton emission was observed in stoichiometric ZnO epilayers grown on Al2O3 substrates by pulsed laser deposition. Absorption and photoluminescence measurements clearly showed the free-exciton emissions at 3.30~3.31 eV. This free-exciton recombination results from the high-quality single-crystalline ZnO epilayers. Temperature-dependent excitonic properties revealed the higher thermal stability of stoichiometric ZnO epilayers with the effective phonon energy, electron-phonon interaction and exciton-phonon coupling of 65.2 meV, 0.093 meV/K and 680 meV, respectively. The strong exciton-phonon coupling has been attributed to the high Frohlich constant due to the strong localization energy in the stoichiometric ZnO epilayers.
Keywords :
absorption; dielectric thin films; electron-phonon interactions; photoluminescence; pulsed laser deposition; semiconductor epitaxial layers; stoichiometry; zinc compounds; Frohlich constant; ZnO; absorption measurements; electron-phonon interaction; exciton-phonon coupling; free-exciton emission; high-quality single- crystalline epilayers; phonon energy; photoluminescence measurements; pulsed laser deposited stoichiometric thin films; stoichiometric epilayers; thermal stability; Absorption; Optical pulses; Phonons; Photoluminescence; Pulsed laser deposition; Spontaneous emission; Sputtering; Temperature; Thermal stability; Zinc oxide; ZnO; exciton-phonon coupling; free excitons; lattice dilation; stoichiometry;
Conference_Titel :
Optoelectronic and Microelectronic Materials and Devices, 2008. COMMAD 2008. Conference on
Conference_Location :
Sydney, SA
Print_ISBN :
978-1-4244-2716-1
Electronic_ISBN :
1097-2137
DOI :
10.1109/COMMAD.2008.4802079
