Influence of Sulfurization Time on Sb₂S₃ Synthesis Using a New Graphite Box Design

In recent years, antimony sulfide (Sb₂S₃) has been investigated as a photovoltaic absorber material due to its suitable absorber coefficient, direct band gap, extinction coefficient, earth-abundant, and environmentally friendly constituents. Therefore, this work proposes Sb₂S₃ film preparation by an effective two-step process using a new graphite box design and sulfur distribution, which has a high repeatability level and can be scalable. First, an Sb thin film was deposited using the RF-Sputtering technique, and after that, the samples were annealed with elemental sulfur into a graphite box, varying the sulfurization time from 20 to 50 min. The structural, optical, morphological, and chemical characteristics of the resulting thin films were analyzed. Results reveal the method's effectivity and the best properties were obtained for the sample sulfurized during 40 min. This Sb₂S₃ thin film presents an orthorhombic crystalline structure, elongated grains, a band gap of 1.69 eV, a crystallite size of 15.25 Å, and a nearly stoichiometric composition. In addition, the formation of a p-n junction was achieved by depositing silver back contact on the Glass/FTO/CdS/Sb₂S₃ structure. Therefore, the graphite box design has been demonstrated to be functional to obtain Sb₂S₃ by a two-step process.