Nitrogen ion implantation effects on the structural, optical and electrical properties of CdSe thin film

Abstract

In the present study, thin films of cadmium selenide (CdSe) are deposited on ITO substrate by electrodeposition method using aqueous solution of 3CdSO4·8H2O and SeO2. These films are implanted with 40 keV N+ ions with different fluencies i.e. 1 × 1015, 5 × 1015, 1 × 1016 and 5 × 1016 ions/cm2 using a beam current of 0.9 µA. The structural, morphological, optical and electrical properties of pristine and nitrogen ion-implanted CdSe thin films are analyzed using XRD, SEM, AFM, UV-PL Spectrophotometer and I–V four probes setup. XRD analysis revealed the effects of nitrogen ions on the structural parameters such as grain size, FWHM, micro strain and dislocation density etc. Crystallanity of the material increased with increase in implantation dose. SEM and AFM analysis show decrease in the surface roughness with implantation. From the optical studies, band gap value decreased from 2.50 to 2.29 eV with increase in N+ implantation doses. Noticeable changes in the electrical properties are also reported. The effect of N+ ion implantation on the properties of CdSe thin films are discussed on the basis of lattice disorder.