Size Dependent Physical Properties of Spray Deposited Nanocrystalline Cd_0.5Fe_0.5Se Thin Films

摘要

Nanostructured Cd_0.5Fe_0.5Se thin films were successfully deposited onto the glass substrates at 573 K temperature using spray pyrolysis technique. The films of thickness 156 to 290 nm were prepared by changing the quantity of spray solution from 10 to 25 mL. The structural and morphological properties of nanostructured Cd_0.5Fe_0.5Se thin films were investigated by XRD, EDAX, SEM and AFM analysis respectively. The XRD analysis shows that the spray deposited Cd_0.5Fe_0.5Se thin films are nanocrystalline in nature with hexagonal crystal structure. The as deposited Cd_0.5Fe_0.5Se thin films are porous in nature with growth of nanotubes and nanodiscs depending upon quantity of spray solution. The AFM analysis shows uniform growth of Cd_0.5Se_0.5Fe material that covers the whole substrate. The electrical resistivity of semiconducting Cd_0.5Fe_0.5Se thin films is of the order of 10⁶ Ωcm and it decreases as the film thickness increases. The thermo-emf measurement confirms the n-type conductivity of Cd_0.5Fe_0.5Se thin films. The optical band gap energy of the deposited Cd_0.5Fe_0.5Se thin film increases from 1.74eV to 2.08eV as the film thickness decreases from 290 to 156 nm.