Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14–0.19 eV at low temperature and 0.27–0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

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► Simple and inexpensive method to dope trivalent Fe in CdSe thin films.
► Fe doped CdSe thin films are highly photosensitive.
► AFM analysis shows uniform deposition of film over the entire substrate surface.
► The band gap energy decreases from 1.74 to 1.65 eV with Fe doping.
► Film resistivity decreases to 6.76 × 104 Ω-cm with Fe doping in CdSe thin films.