Browsing by Author "TSAI, CT"

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HIGH ORIENTATION CDS THIN-FILMS GROWN BY PULSED LASER AND THERMAL EVAPORATION
(1992-05-01)
DAI, CM
;
HORNG, L
;
HSIEH, WF
;
SHIH, YT
;
TSAI, CT
Undoped CdS films have been grown by pulsed laser evaporation (PLE) and thermal evaporation (TE) techniques on Corning's 7059 glass at a substrate temperature between room temperature and 250-degrees-C. The deposition rates are 0.07 angstrom/s for PLE and 60 angstrom/s for the TE technique. These as-deposited films have high (002) preferred orientation by both techniques even without preheating the substrate. However, films deposited by PLE have more preferred orientation and larger grain size. These features make the PLE films have sharper Raman peaks, smaller Raman shift of surface mode and more overtones of longitudinal optical phonon mode observed than those in TE films. The transparency of PLE or TE films for wavelengths which are larger than that of absorption edge is around 90% on average.
RAMAN INVESTIGATIONS OF THE SURFACE-MODES OF THE CRYSTALLITES IN CDS THIN-FILMS GROWN BY PULSED LASER AND THERMAL EVAPORATION
(1991-06-15)
CHUU, DS
;
DAI, CM
;
HSIEH, WF
;
TSAI, CT
;
電子物理學系
CdS films have been grown on Corning glass by pulsed laser evaporation (PLE) and thermal evaporation (TE) techniques at a substrate temperature between room temperature and 250-degrees-C. The quality of these films is investigated by resonance Raman scattering, x-ray diffraction and optical transmittance. Our results reveal that the Raman shifts of the surface phonon mode are observed with 300 and 297 cm-1 by PLE and TE techniques, respectively, and as many as four overtones are obtained by PLE method. The difference of Raman shift between these two techniques are caused by the discrepancy of crystallite sizes which is larger for PLE technique. The crystallite sizes are in the range of 200-500 angstrom in diameter. Highly oriented films have been grown by both of the techniques even when the substrate is at room temperature.