Growth of hierarchical strontium incorporated cadmium sulphide for possible application in optical and electronic devices

Abstract

In this work, we have incorporated strontium (Sr) into cadmium sulphide (CdS) complex to explore its effect on optical and electrical properties. In this regard Sr composited CdS and a bared CdS were prepared by hydrothermal technique. X-ray diffraction pattern of the materials were analyzed to obtain their crystalline structure, size and internal lattice strain. The compositional details were obtained from SEM-EDAX study. The optical properties of the films of synthesized materials were analyzed. The dependency of refractive index on incident photon energy was studied in detail for each material. The dispersion energy related parameters, dielectric relaxation constant and optical conductivity followed by dispersion of the refractive index were determined and discussed by employing the single electronic oscillator model. From wavelength dependent refractive index data, the plasma frequency, ratio of free charge carrier concentration to effective mass, lattice dielectric constant and high frequency dielectric constant were calculated to determine the discrepancy of the compounds. The third order optical susceptibility was analyzed to check their potential ability of performance in optical limiter and optical switching device application. The electrical characterization was performed by measuring the current–voltage characteristics of structure ITO/CdS:Sr/Al and ITO/CdS/Al. The rectifying I–V showed improved On/Off ratio under dark (25.03 and 19.98) and light (35.51 and 25.09) for ITO/CdS:Sr/Al compared to ITO/CdS/Al. The dark and photoconductivity of the film were also determined for both the films. The time dependent current response was analyzed at constant bias voltage ±1 V.