Sb2s3 powder

Antimony powder (Sb, 99.999%), elemental sulfur (S, 99.999%), elemental selenium (Se, 99.999%), Sb₂S₃ powder (99.999%) and Sb₂Se₃ powder (99.999%) were all purchased from Alfa Aesar. Anhydrous hydrazine (N₂H₄, 98%) was purchased from Sinopharm Group Co. Ltd. All chemicals were used without any purification.

Raman analysis was performed on the hydrazine precursor solutions including Sb-S, Sb-Se, Sb-S-Se and S-Se solutions in a backscattering confocal configuration at room temperature. A LabRAM in Via Raman system was applied for measurement, and the unpolarized light was generated through a 532 nm Ar laser with power adjusted to 50 mW. Prior to measurement, each solution was sealed in a glass vial by parafilm in order to minimize oxygen and moisture exposure. X-ray diffraction (XRD) characterization (Philips, X pert pro MRD, with Cu Kα radiation, λ = 1.54178 Å) was performed on the annealed Sb₂(S_1-xSe_x)₃ thin films prepared on TiO₂ substrates. The compositions of the thin films were obtained through energy dispersive spectroscopy (FEI Quanta 600 scanning electron microscope, 20 kV). Sb₂S₃ powder (99.999%, Alfa Aesar) and Sb₂Se₃ powder (99.999%, Alfa Aesar) were used as standards for the calibration of EDS measurements. Scanning electron microscopy (FEI Nova NanoSEM450, without Pt coating) and UV-vis-NIR transmission spectroscopy (Perkin Elmer Instruments, Lambda 950 using integrating sphere) was performed on the Sb₂(S_1-xSe_x)₃ films to determine the surface morphology and band gap, respectively.