Influence of different concentrations of SbCl 3 salt on the properties of Sb 2 S 3 nanobars prepared by the solvothermal method for solar cell application

Abstract

Antimony sulfide (Sb 2 S 3 ) nanobars are synthesized by the solvothermal method using different concentrations of the antimony chloride salt (SbCl 3 )at 180 °C for 14 h. The effects of 0.75, 0.8, 0.85, and 0.9 mmol of SbCl 3 on the compositions, morphologies, and phases of the product are investigated. Raman spectroscopy indicates that the product corresponds to the pure orthorhombic phase of Sb 2 S 3 . Transmission electron microscopy indicates that the appearance of the as-synthesized Sb 2 S 3 resembles that of nanobars with a typical width of 200–300 nm, which predominantly grow along the [001] direction. Chemical composition analysis confirms that the sample is composed of S and Sb, and the atomic ratio of Sb/S is close to 2:3, which is confirmed by X-ray photoelectron spectroscopy. The phase-pure Sb 2 S 3 nanobars exhibit an optical energy gap between 1.5 eV and 1.74 eV and an absorption coefficient of approximately 10 4 cm −1 , which would thus be suitable for use in photovoltaic applications. Scanning electron microscopy results indicate that the Sb 2 S 3 thin-film-based nanobars are compact and smooth with a grain size of more than 3 µm. The best results reported here are for the solar cell structure Mo/Sb 2 S 3 /CdS/ITO/Ag with an open circuit voltage of 451 mV, short circuit current density of 12.47 mA/cm 2 , fill factor of 0.61, and conversion efficiency of 3.46%.