Moderate-temperature fabrication of BaZrS₃ thin films via dithiocarbamate-based solution processing and oxygen-sink boron sulfurization

Chalcogenide perovskites are increasingly recognized as promising light-absorbing materials because of their low toxicity, cost-effectiveness, and abundance. In this class, BaZrS₃ is particularly attractive because of its outstanding optoelectronic properties. However, practical device applications are limited by the high-temperature synthesis (>900 °C), creating an ongoing demand for low-temperature, solution-processable methods. Existing low-temperature approaches are often constrained to nanocrystal- or slurry-based synthesis or involve complex sulfurization steps with toxic gases, limiting their scalability and reproducibility. This paper introduces a dithiocarbamate-based molecular ink strategy that enables the use of soluble metal precursors and lower processing temperatures. This method allows the formation of a homogeneous solution that facilitates the fabrication of BaZrS₃ thin films at moderate temperatures via a simplified sulfurization process using boron sulfide within a graphite box. The approach was used to fabricate pure BaZrS₃ thin films at 650 °C that exhibit a distinct photocurrent response. This straightforward method not only highlights the influence of chemical coordination in solution but also represents a significant advancement in BaZrS₃ fabrication, offering an accessible pathway toward scalable production for solar cell applications.