Al3+ Doped In2S3 Thin Films: Structural and Optical Characterization
Parisa Esmaili, Somayeh Asgary
Abstract
Aluminum indium sulfide thin films have been synthesized by chemical bath deposition (CBD) method at different [Al/In] molar ratio concentrations. Al3+ ions by different concentration have doped from aluminium chloride source. The crystallography, phase transitions, element analysis, and morphology of In2S3: Al thin films have been studied by X-ray diffraction, SEM, EDS, and AFM analysis. Optical transmittance and reflectance measured in the UV-VIS wavelength range by spectrophotometer and electrical resistivity investigated by Hall effect. XRD results showed Al doping had strong effects on the film’s crystallinity, and changed its crystalline nature to amorphous. According to SEM and AFM results, the morphology and nanostructure of In2S3 thin films changed completely after Al doping. After Al doping, a densely packed surface morphology with a higher transparency and wider band gap energy obtained. Band gap energy of thin films varied from 3 to 3.59 eV as a function of the [Al/In] ratio.