Properties of CdS films doped with magnesium and fluorine

Abstract

Nanostructured CdS thin films co-doped with Mg and F were prepared on glass substrates maintained at 400°C by spray technique using perfume atomiser. Structural, morphological, optical and electrical properties of the films were investigated in order to study the effect of Mg, F doping concentration. XRD patterns confirm that both undoped and co-doped CdS films exhibit hexagonal crystal structure with preferential orientation along the (0 0 2) plane. Crystallite size decreased from 33.19 to 24.51 nm with increase in Mg, F concentration. Increased transparency and blue shift in optical band gap from 2.48 to 2.75 eV is observed with increase in Mg, F concentration. All the films have resistivity in the order of 10⁻² Ω cm which decreased with co-doping. Improved optical transparency, widened band gap and decreased resistivity were observed for the CdS films simultaneously doped with Mg and F.

Keywords:

• Thin films
• Crystallites
• Energy band gap
• Resistivity

Acknowledgements

The authors thank the Head, Department of Physics and Mr Karthik, Alagappa University for the XRD measurements.