Márquez, J.A.; Rusu, M.; Hempel, H.; Ahmet, I.Y.; Kölbach, M.; Simsek, I.; Choubrac, L.; Gurieva, G.; Gunder, R.; Schorr, S.; Unold, T.: BaZrS3 Chalcogenide Perovskite Thin Films by H2S Sulfurization of Oxide Precursors. Journal of Physical Chemistry Letters 12 (2021), p. 2148-2153
The earth-abundant ternary compound BaZrS3, which crystallizes in theperovskite-type structure, has come into view as a promising candidate for photovoltaicapplications. We present the synthesis and characterization of polycrystalline perovskite-typeBaZrS3thinfilms. BaZrO3precursor layers were deposited by pulsed laser deposition andsulfurized at various temperatures in an argon-diluted H2S atmosphere. We observe increasingincorporation of sulfur for higher annealing temperatures, accompanied by a red shift of theabsorption edge, with a bandgap ofEg= 1.99 eV and a large absorption strength >105cm−1obtained for sulfurization temperatures of 1000°C. X-ray diffraction analysis and SEM indicateenhanced crystallization at the higher annealing temperatures, but no evidence for a crystallinesolid solution between the BaZrO3and BaZrS3phases is found. The charge carrier summobility estimated from optical-pump−terahertz-probe spectroscopy indicates increasingmobilities with increasing sulfurization temperature, reaching maximum values of up to∼2cm2V−1s−1.