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Herein, we report engineering of nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu + , In 3+ and Se 2− ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200 °C in air for 1 h and further characterized for structural, optical and electrical properties using UV–Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I – V measurement to investigate the charge conduction phenomenon. The characteristic (1 1 2) and (1 1 0) planes in XRD and the electron diffraction pattern could confirm the formation of CuIn 3 Se 5 . The chemical composition and the band gap energy E g = 1.4 eV of the nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction thin-films were confirmed using XPS and the absorbance spectra, respectively. Based on the data and energy band gap calculations of CuIn 3 Se 5 and CdS thin films, the probable band alignment between the nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction is proposed. |
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