In this work we have studied the optical properties of the thin CuInS2
and In-S layers prepared by airless spray << P.S.A. >>. The study of
the optical properties from the ellipsometric measure realized in the
interval energy of incident photons [1.5-4] eV, has showed that the re
fraction index n, and the extinction coefficient k, vary in the interv
al [1.8-2.3] and 10.45-0.801 respectively. The absorption coefficient
a of the thin CuInS2 layers realized for different ratios x of the con
centrations in the spray solution (x = [CuI]/[InIII]) is high with val
ues varied between (5 x 10(4) and 18 x 10(4) cm-1). The direct gap ene
rgy of the thin CuInS2 layers of the order of 1.38 eV. In the same way
, we study the spectrum variation of n1(lambda) and k1(lambda) of the
thin In-S layers, realized for two values of ratio y of the concentrat
ion in the spray solution (y = [In3+]/[s2-]). shows that for the value
of y = 0.6 (material beta-In2S3) the refraction index is higher than
that of the thin layer obtained for the value of y = 0.75 (material In
6S7) [1], and that the extinction coefficient is lower than that of In
6S7. For In-S thin layers, a is also high with values varing between 2
x 10(4) and 12 x 10(4) cm-1. The direct band gap of materials beta-In
2S3 and In6S7 are 2.22 eV and 1.94 eV respectively. The heat treatment
under vacuum at 573 K during two hours improves the optical quality o
f the thin << p >> type CuInS2 Layer.