Thin films of AgInTe2 were prepared on quartz substrates by a flash
evaporation technique at substrate temperature ~303 K. The
compositions of both the bulk and thin films, with thickness (~208–350 nm), were checked using energy dispersive X-ray spectroscopy (EDX). X-ray
diffraction (XRD) measurements showed that AgInTe2 compound is
characterized by a tetragonal structure while the as deposited films have
amorphous nature. On annealing at 423 and 573 K (for two hours and under
vacuum ~10−3 Pa), the films were identified to be single-phase, polycrystalline with a preferred (112) orientation. The optical
properties of the films were investigated using spectrophotometric
measurements of transmittance and reflectance at normal incidence in the
wavelength range (~500–2500 nm). The refractive index (n) and the
absorption index (k) of AgInTe2 were determined from the absolute values
of the measured transmittance and reflectance. It was found that both (n)
and (k) depend markedly on the temperature of heat treatment. The
dispersion of refractive index in AgInTe2 was analyzed using the
concept of the single oscillator model. Within this concept some dispersion
parameters were determined for as deposited and annealed flash evaporated
AgInTe2 films at 423 K for 2 h. The calculated values of β
indicated that AgInTe2 films belong to ionic class. The ratio of the
free carrier concentration to the effective mass (N/m*) were, also
determined. The analysis of the absorption coefficient indicated that, this
ternary chalcopyrite compound has three allowed direct transitions
corresponding to three energies gaps Eg1, Eg2 and Eg3. The
crystal field (Δcf), the spin orbit (Δso) and
the deformation potential (b) were calculated for both as deposited and
annealed flash InAgTe2 films at ~423 K for 2 h.