INFLUENCE OF PULSE WIDTH ON CDS FILM PREPARED BY YAG LASER ABLATION

CdS films were deposited on glass substrates using two kinds of YAG lasers: one with a long pulse width of tau=100 mus and one with a short pulse width of tau=15 ns. Scanning electron microscopy observation and X-ray diffraction patterns showed that the film formed by the long pulse laser with a low energy density has a smooth surface and highly oriented texture. Resistivity is distributed in a wide range: 100-2000 OMEGA.cm and 10-100 OMEGA.cm for the films formed by long and short pulse lasers, respectively. Measurement of optical transmission spectra suggests the existence of an impurity level in the low resistivity film. Streak image of the plume obtained using an image converter camera showed that the average velocity of ablated luminous particles is about 5 X 10(4) cm/s for long pulse laser ablation and (3-9) X 10(5) cm/s for the short one.