Spectroscop ic ellip sometry ( SE) was emp loyed to characterize ZnO thin films p repared by pulsed laser
deposition ( PLD) on Si (100) substrates at various temperature of 400, 500, 600 and 700 ℃. The refractive indices
( n) and extinction coefficients ( k) of the ZnO filmswere calculated in the spectral range of 400～800 nm for each
deposition temperature by fitting the ellip sometic parameters based on a three2layers dispersion with Cauchymodel. It
was found that the op tical constants were significantly affected by the substrate temperature. Through analyzing the
crystalline structures and surface morphologies of ZnO thin films grown at different substrate temperature by XRD and
atomic force microscopy (AFM) , respectively, the variation of the refractive index can be attributed to the changes of
the packing density of the thin film. After comparing the results obtained at different grown temperature, itwas sug2
gested 600 ℃might be the op timum deposition temperature for growing dense ZnO filmswith high op tical and crystal2
line quality