著者

Nagase Toshimi Ooie Toshihiko Makita Yoji KASAISHI Shuji NAKATSUKA Masahiro MIZUTANI Nobuyasu

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 1, Regular papers & short notes (ISSN:00214922)

巻号頁・発行日

vol.40, no.11, pp.6296-6303, 2001-11-15

被引用文献数

1 9

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Morphology, structure and photoluminescence (PL) properties of zinc oxide (ZnO) films prepared by KrF-excimer-laser irradiation of sol-gel-derived precursors were studied. The precursors with a film thickness of 100 or 180 nm were irradiated by the laser at various energy fluences (Ef). Atomic force microscopy and transmission electron microscopy observations revealed that the laser irradiation at an Ef ≧100mJ/cm^2 produced crystal growth of close-packed ZnO crystals in an upper layer. Laser irradiation at a high Ef (150mJ/cm^2) of the thinner precursor produced a remarkable crystallization throughout the film, resulting in larger grain size and smooth film surface. Our observation results suggest that the crystallization proceeds by sintering or solidification via melting. The films obtained at Ef ≧ 100mJ/cm^2 showed green PL. The PL spectra were not significantly influenced by the excitation wavelength except for the thinner film irradiated at a high Ef (150mJ/cm^2); it showed a striking increase in the green PL intensity when excited at 275 nm instead of 325 nm. The unique excitation-wavelength dependence may be related to its characteristic threshold of electron excitation.