Investigations on the Properties of Nanostructured Mg-Doped Sn₂S₃ Thin Films towards Photovoltaic Applications

Abstract

This paper reports the synthesis, crystal structure, surface morphology, optical and electrical properties of Mgdoped Sn2S3 thin films deposited by spray pyrolysis technique. All the films exhibit orthorhombic crystal structure with a (211) preferential orientation. Crystallite size calculations based on the Debye-Scherrer formula indicated that the Sn2S3 crystallite size increases with Mg content from 27.97 nm to 33.58 nm. Scanning electron microscopy images showed that all the films were very smooth composed of nanoneedle and nanoplate shaped grains. The band gap energy of the films exhibits a blue shift from 1.94 eV to 2.09 eV with increase in Mg concentration. Resistivity values of the undoped and Mg-doped Sn2S3 films were found to be in the order of 0.1 Ωcm. From the obtained results it is observed that the Sn2S3 film coated with 2 wt% Mg concentration exhibits better physical properties.

Role of Cu/S ratio and Mg doping on modification of structural and optical characteristics of nano CuS

“…Cu 1−x Mg x S (x = 0-0.4, step 0.1) was prepared using a 1:2 ratio between copper acetate to thiourea. 24 Furthermore, the crystallite size diminished as the amount of sulfur increased in CuS samples in contrast to the result obtained in CuS nanocrystal prepared by a simple chemical route; as the amount of S increases in the sample, the sample exhibited better crystallinity. MAUD software 21 based on Rietveld profile method 22 was used in order to determine the crystal structure and microstructure from Xray diffraction data (XRD) of the samples which were measured using X'pert MPD, Philips (2θ = 10°-80°, step = 002°, counting time = 2 seconds, Cu-K α ).…”

“…A similar effect was obtained in Mg-doped Sn 2 S 3 thin films where the lattice parameter increased as the amount of Mg increased. 24 Furthermore, the crystallite size diminished as the amount of sulfur increased in CuS samples in contrast to the result obtained in CuS nanocrystal prepared by a simple chemical route; as the amount of S increases in the sample, the sample exhibited better crystallinity. 11 The crystallite size increased as amount of Mg increased.…”

“…The broad PL emissions peaks can be decomposed into sub-emission peaks using Gaussian fitting as shown in Figure 6. 24 Mgdoped Ag 2 S colloidal nanoparticles exhibited orange emission. It is noticed that the number of bands increased with the increased Cu:S ratio.…”

“…MAUD software 21 based on Rietveld profile method 22 was used in order to determine the crystal structure and microstructure from Xray diffraction data (XRD) of the samples which were measured using X'pert MPD, Philips (2θ = 10°-80°, step = 002°, counting time = 2 seconds, Cu-K α ). 24 Figure 2A, Figure 3 shows the Fourier transforms infrared spectroscopy spectra (FTIR) for CuS with different Cu:S ratio and Mgdoped nano CuS samples measured at room temperature in the range of 400-4000 cm −1 . UV-Vis, photoluminescence (PL) and Fourier transform infrared (FTIR) were conducting by Shimadzu UV-3101PC UV-Vis-NIR scanning spectrometer, luminescence spectrophotometer (RF-1501 SHIMADZU, Ltd) with a resolution of 10 nm and Bruker Tensor 27 FTIR spectrometer, respectively.…”

“…A similar effect was observed in Mg-doped Sn 2 S 3 thin films where crystallite size enlarged from 28 to 33 nm as the amount of Mg-doped increased from 0% to 3%. 24 Figure 2A Figure 3 shows the Fourier transforms infrared spectroscopy spectra (FTIR) for CuS with different Cu:S ratio and Mgdoped nano CuS samples measured at room temperature in the range of 400-4000 cm −1 . It is obvious from the figure that all samples have the same absorption peaks, which indicated that the structure of CuS was not altered by doping or changing of the Cu to S ratio.…”