Barium zirconium sulfide (BaZrS3) is an earth-abundant and environmentally friendly chalcogenide perovskite with promising properties for various energy conversion applications. Recently, strong focus has been put into exploring different synthesis pathways for efficient high-quality thin film growth. Among them, sulfurization of oxide precursors has been suggested as viable solution for effective synthesis, especially from perspective of circumventing the difficulty of handling alkali earth metals. In this work, we explore in detail the mechanism and efficiency of BaZrS3 formation from BaZrO3 oxide precursors at various sulfurization temperatures. We propose a formation mechanism of BaZrS3, which is based on a two-step reaction involving an intermediate amorphization step of the BaZrO3 crystal phase. We show that the diffusion of S and the energetic barrier associated to BaZrS3 crystallization are both rate-limiting steps of this reaction at lower sulfurization temperatures (< 800 {\deg}C). At higher sulfurization temperatures >=800 {\deg}C, a larger rate of conversion from oxide to sulfide phase is observed. However, even with the increased conversion rate, only films sulfurized at 1000 {\deg}C have significantly large grains that make them suitable for optoelectronic devices. Finally, we observe formation of stoichiometric BaZrS3 ([Ba]/[Zr] = 1) even under non-equilibrium conditions, such as Zr-rich oxide precursor, with the extra Zr forming ZrO2 phase at the substrate-film interface. This marks BaZrS3 quite unique among the other types of chalcogenides, such as chalcopyrites and kesterites, which can accommodate quite a large range of non-stoichiometric compositions.

中文翻译：

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硫化氧化物前驱体制备 BaZrS3 硫属钙钛矿的可行性

钡锆硫化物 (BaZrS3) 是一种富含地球且环境友好的硫属化物钙钛矿，在各种能源转换应用中具有广阔的前景。最近，人们将重点放在探索用于高效高质量薄膜生长的不同合成途径上。其中，氧化物前体的硫化已被建议作为有效合成的可行解决方案，特别是从规避处理碱土金属的困难的角度来看。在这项工作中，我们详细探讨了在不同硫化温度下从 BaZrO3 氧化物前体形成 BaZrS3 的机制和效率。我们提出了 BaZrS3 的形成机制，该机制基于涉及 BaZrO3 晶相的中间非晶化步骤的两步反应。我们表明，S 的扩散和与 BaZrS3 结晶相关的能量势垒都是该反应在较低硫化温度（< 800 {\deg}C）下的限速步骤。在 >=800 {\deg}C 的较高硫化温度下，观察到从氧化物相到硫化物相的较大转化率。然而，即使转化率提高，只有在 1000 ℃ 硫化的薄膜具有显着大的晶粒，使其适用于光电器件。最后，我们观察到化学计量 BaZrS3 ([Ba]/[Zr] = 1) 的形成，即使在非平衡条件下，例如富含 Zr 的氧化物前体，额外的 Zr 在基板-薄膜界面形成 ZrO2 相。这标志着 BaZrS3 在其他类型的硫属化物中非常独特，例如黄铜矿和黄钾铁矿，