Antimony sulfide (Sb2S3) from group
III2–VI3 is a very capable semiconducting
candidate
for tandem solar cells owing to its suitable optoelectronic properties.
The doping of Ag tailors the optoelectronic and surface properties
for different applications. In the current study, Ag/Sb2S3 bilayer films were annealed at different temperatures.
The cross-sectional view by FESEM inferred the bilayer and the interdiffusion
of Ag into the Sb2S3 layer. The porosity in
the film’s surface decreased upon annealing, as seen from the
surface morphology. The confirmation of the elements was inferred
from the EDS data, while the amorphous structure was verified from
X-ray diffraction analysis. The effect of annealing on the different
optical parameters was determined from the UV–vis-NIR spectra
and related calculations. The optical bandgap, extinction coefficient,
refractive index, and dielectric parameters changed with the intermixing
of Ag into the Sb2S3 layer upon annealing. The
χ(3) value changed from 4.560 × 10–18 to 2.086 × 10–18 m2/V2, and the nonlinear refractive index varied from 4.324 × 10–17 to 2.165 × 10–17 m2/V2 upon annealing. The hydrophilicity increased with
annealing, as found from the contact angle measurement. The change
in photoconductivity upon annealing is very useful for visible light
photodetection. The computational study supported the changes in the
films upon annealing.