Partially replacing DMF with eco-friendly solvents in the fabrication of Sb2S3 photoactive layers for solar cells

Antimony sulfide (Sb 2 S 3 ) is an inorganic compound consisting entirely of earth-abundant elements of low toxicity, low cost, and remarkable chemical and thermal stability, making it promising for next-generation photovoltaic technology, supercapacitors, photodetectors and thermoelectric devices. When employing homogeneous molecular ink-based processes, the choice of solvent is critical to ensure good precursor solubility and promote the formation of smooth and uniform films, which are key factors for improving efficiency in optoelectronic devices. Dimethylformamide (DMF) is the most utilized solvent to prepare the Sb 2 S 3 precursor solutions due to the good dissolution of SbCl 3 and thiourea, the constituents that form the (SbCl 3 -thiourea)-DMF complex. However, it is classified as toxic and requires careful handling. In this paper, we investigate the partial replacement of DMF with less hazardous alternatives, such as gamma butyrolactone (GBL), ethanol (EtOH), and dimethyl sulfoxide (DMSO), for the preparation of Sb 2 S 3 films. Without applying additional surface or post-deposition treatments, Sb 2 S 3 films with a specific texture were obtained. When integrated into solar cells, these Sb 2 S 3 absorbers delivered power conversion efficiency values comparable to those reported for Sb 2 S 3 films deposited by the conventional chemical bath deposition (CBD) method. The present study demonstrates that combining partial substitution of DMF with eco-friendly solvents and simple solution deposition techniques enhances solar cells efficiency while reducing toxicity in the fabrication process of Sb 2 S 3 -based electronic devices.