Abstract
In this study, we report the fabrication of cadmium-doped indium sulfide thin films (In
2
S
3
:Cd) using a low-cost nebulizer-aided spray pyrolysis process at 350 °C on glass substrates for photo-sensing applications. The impact of 0, 2, 4, and 8 wt% cadmium concentrations on the structure, morphology, optical properties, and photo-sensing capabilities of In
2
S
3
thin films were examined systematically. From X-ray diffraction (XRD) analysis, the major peak is located in the (103) plane for all Cd-doped In
2
S
3
thin film samples, and the maximum crystallite size for the 4 wt% sample is 59 nm. The field emission scanning electron microscope (FESEM) image revealed a homogenous large-grained surface of Cd-doped In
2
S
3
film that completely covered the substrate. UV–Vis absorption analysis demonstrated good absorption for all thin film samples in the visible and ultraviolet regions of the electromagnetic spectrum, particularly, the 4% Cd-doped concentration showed excellent absorption as is observed from Tauc relation. The highest PL intensity at 680 nm was observed for the sample coated with 4 wt% of Cd. Under UV light, the
I
–
V
behavior depicts a light current of 1.06 × 10
–6
A for a 5 V bias voltage. The In
2
S
3
: Cd (4%) sample had the highest responsivity of 2.12 × 10
−1
A/W and a detectivity of 1.84 × 10
11
Jones, with a high EQE of 50%. The study manifests that the developed Cd (4%)-doped In
2
S
3
thin film sample might be better suited for the application of photodetectors.