Synthesis of Nanocrystalline Sn x Cd1−x S Thin Films Capped with Thioglycerol and Methanol (TGM) and Study of Optical and Structural Properties

• Published in: Journal of electronic materials Vol. 48; no. 4; pp. 2152 - 2161
• Main Authors: Pandey, Suman, Das, Ruby
• Format: Journal Article
• Language: English
• Published: Warrendale Springer Nature B.V 01.04.2019
• Subjects: Aqueous solutions; Cadmium acetate; Cadmium sulfide; Diffraction patterns; Doping; Electron diffraction; Electron microscopes; Infrared spectroscopy; Low concentrations; Methanol; Nanocrystals; Nanoparticles; Near infrared radiation; Optical properties; Photoconductivity; Photoluminescence; Thickness; Thin films; Tin; Tin chloride; X-ray diffraction
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-019-06992-3

Nanostructured CdS (nCdS) and ternary SnxCd1−xS thin films capped with thioglycerol and methanol in 1:1 ratio in aqueous medium were prepared using hydrated stannous chloride (SnCl2·2H2O), anhydrous cadmium acetate (CH3COO)Cd·2H2O and thiourea (CS(NH2)2) as sources of Sn, Cd and S ions, respectively. Thickness of the film drastically decreases for low concentrations (0–2%) of Sn doping, then increases for (2–3%) and 5% Sn doping. Effects of Sn concentration variation on the optical properties, photoluminescence and structural properties of the nanoparticles were studied. The optical transmittance measurement using ultraviolet–visible–near infrared spectroscopy showed more than 80% transparency in the wavelength range 450–800 nm for 3% and 5% Sn doping. The direct optical band gap value of nanoCdS thin films was obtained as 2.91 eV, which decreased with Sn doping for its varying concentrations. Photoconductivity gain was negligible. A decrease in intensity of lower wavelength emission at 430 nm in nCdS was observed to have (2–5)% Sn content. X-ray diffraction patterns and selected area electron diffraction patterns confirmed formation of the nanocrystalline hexagonal CdSnS phase. Scanning electron microscope and transmission electron microscope measurements of the CdSnS thin films show that the particle size lies well under 20 nm.