Chalcogenide perovskites are a class of materials that have recently garnered interest due to their good environmental stability and low band gaps, often in the ideal range for applications related to solar cells.
1 Chalcogenide perovskites generally have the formula of ABX
3, where A represents a divalent cation such as Sr
2+, or Ba
2, B is a tetravalent cation such as Zr
4+, or Hf
4+, and X is a divalent anion such as S
2- or Se
2. In literature only a small number of chalcogenide perovskites have been experimentally made with BaZrS
3 being the most extensively studied out of them due to its comparatively lower synthesis temperatures and higher thermodynamic favourability.
1 BaZrS
3 has a bandgap of 1.8 eV which makes it an excellent choice for a silicon-based tandem solar cell.
1 One of the greatest challenges of using chalcogenide perovskites for applications in solar cells is that temperatures greater than 800°C have traditionally been required for synthesis, making them incompatible with substrates and contacts used in solar cell production. For solution-processed synthesis of BaZrS
3, the lowest temperatures that have been reported in literature by Zilevu et.al., range from 365 °C to 275 °C where the nanoparticles synthesized at the lower temperatures showed structural distortions. This was done using metal amide barium and zirconium precursors in oleylamine solution and the synthesized BaZrS
3 did not show any significant luminescence. In this paper, we present a solution-processed route using organometallic precursors in carbon disulfide solution used to synthesize luminescent BaZrS
3 at a temperature of 575°C with sulfurization for as little as one hour.
The synthesis process we developed utilizes organometallic barium and zirconium precursors dissolved in a solvent containing sulfur to form a precursor ink. This ink was then blade coated onto a glass substrate and then annealed in an atmosphere containing sulfur at a temperature of 575°C for times ranging from 1 hour to 16 hours. The material resulting from this process show a PXRD diffraction pattern with a ternary phase and a Raman spectrum that corresponds with previously documented standards. The material also showed a photoluminescence peak centered at 1.77 ev.
(1) Sopiha, K, Comparotto, C, Márquez, J. A, Scragg, J. J. S. Chalcogenide Perovskites: Tantalizing Prospects, Challenging Materials. Advanced Optical Materials, 2022. https://doi.org/10.1063/1.4879659
(2) Zilevu, D., Parks, O. O., & Creutz, S. E. Solution-phase synthesis of the chalcogenide perovskite barium zirconium sulfide as colloidal nanomaterials. Chemical Communications 2022, 58(75), 10512â10515. https://doi.org/10.1039/d2cc03494h
