Structural, optical and vibrational studies of Na+ doped Cd0.8Zn0.2S semiconductor compounds

• Published in: Journal of alloys and compounds Vol. 581; pp. 805 - 811
• Main Authors: Yellaiah, G., Hadasa, K., Nagabhushanam, M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.12.2013; Elsevier
• Subjects: Co-precipitation technique; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Density; Dopants; EDS; Exact sciences and technology; Fourier transforms; FTIR spectroscopy; Lattice dynamics; Optical band gap; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Phonons and vibrations in crystal lattices; Physics; Scanning electron microscopy; Semiconductors; Sodium; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Wurtzite; X-ray diffraction; Zinc; X-ray diffraction; Optical band gap; EDS; Co-precipitation technique; FTIR spectroscopy; Fourier transform spectroscopy; Photonic band gap; Polycrystals; XRD; Sodium ions; Vibrations; Energy gap; Crystallites; Optical properties; Absorption spectra; Fourier-transformed infrared spectrometry; Optical absorption; Coprecipitation; Crystal structure; Scanning electron microscopy; Electronic properties; Impurity density; Interstitials; Dispersive spectrometry; Zinc; Hexagonal lattices; Sodium; Vibrational modes; Wurtzite structure; Porosity; Semiconductor doping
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.07.191

FTIR spectra of Cd0.8Zn0.2S: Nx (x=0.2mol%). [Display omitted] •The energy band gaps of Cd0.8Zn02S: Nasamples were estimated.•Density and porosity percentages were calculated.•From the FTIR study CdS and ZnS stretching bonds were detected. Cd0.8Zn0.2S semiconductor powders doped with different amounts of sodium have been synthesized by controlled co-precipitation technique. X-ray diffraction (XRD), Scanning electron microscope (SEM), Optical absorption and Fourier transform infrared spectroscope (FTIR) studies have been done on all these samples. XRD studies have revealed that the samples are polycrystalline with an average crystallite size ranging from 29 to 55nm and they crystallize in the hexagonal form with wurtzite structure. The optical measurements revealed that the samples possess direct band gap and the band gap increases with an increase in the dopant concentration. The vibrational modes of Cd–S and Zn–S were obtained from FTIR studies and found to be at 812–618cm−1 respectively. Experimental and theoretical (XRD) densities were calculated and analyzed. Density from XRD and porosity in percentage varied from 92% to 94% and 5% to 8% respectively. The elemental analysis of the compounds was done by energy dispersive spectroscopy (EDS) and found that the cadmium, zinc, sulphur and sodium elements were present in the compound as per the composition taken. From the theoretical estimations it is understood that the dopant (Na) occupies the interstitial of CdZnS.