OPTICAL AND STRUCTURAL-PROPERTIES OF ANTIMONY-DOPED CDS THIN-FILMS

Citation
Lp. Deshmukh et al., OPTICAL AND STRUCTURAL-PROPERTIES OF ANTIMONY-DOPED CDS THIN-FILMS, Materials chemistry and physics, 39(4), 1995, pp. 278-283
Citations number
17
Categorie Soggetti
Material Science
ISSN journal
02540584
Volume
39
Issue
4
Year of publication
1995
Pages
278 - 283
Database
ISI
SICI code
0254-0584(1995)39:4<278:OASOAC>2.0.ZU;2-0
Abstract
Optical and structural investigations of antimony-doped cadmium sulphi de thin films prepared by a modified chemical deposition process are d escribed. The samples were prepared in an aqueous medium at a depositi on temperature of 85+/-2 degrees C and a pH of around 8.5. The samples were doped with various concentrations of Sb3+ in the concentration r ange 0.005-1 wt.%. Measurements of the absorption coefficient in the e nergy range 1.6-3.5 eV for both CdS and CdS:Sb crystalline thin films have been carried out. A careful analysis of the absorption coefficien ts indicated the crystalline character of the samples studied; a simil ar diagnosis was obtained from the X-ray and SEM analyses. The absorpt ion coefficient is of the order of 10(4) cm(-1), and the optical energ y bandgap decreases with increasing doping concentration, typically fr om 2.47 to 1.7 eV. The absorption edge shifts towards the higher-wavel ength side and becomes broader as the doping concentration is increase d. The samples are polycrystalline, and the crystallinity increases af ter doping up to a 0.075 wt.% doping level and decreases thereafter. I n both cases the samples consist of phases of cubic and hexagonal stru ctures. Additional peaks corresponding to Sb2S3 orthorhombic phases an d some other small peaks due to excess Cd and S have also been observe d.