Kayastha Prakriti, Longo Giulia, Whalley Lucy D
Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne NE1 8QH, United Kingdom.
ACS Appl Energy Mater. 2024 Apr 5;7(24):11326-11333. doi: 10.1021/acsaem.3c03208. eCollection 2024 Dec 23.
The chalcogenide perovskite BaZrS has strong visible light absorption and high chemical stability, is nontoxic, and is made from earth-abundant elements. As such, it is a promising candidate material for application in optoelectronic technologies. However, the synthesis of BaZrS thin-films for characterization and device integration remains a challenge. Here, we use density functional theory and lattice dynamics to calculate the vibrational properties of elemental, binary, and ternary materials in the Ba-Zr-S system. This is used to build a thermodynamic model for the stability of BaZrS, BaS , and ZrS in equilibrium with sulfur gas across a range of temperatures and sulfur partial pressures. We highlight that reaction thermodynamics are highly sensitive to sulfur allotropes and the extent of allotrope mixing. We use our model to predict the synthesis conditions in which BaZrS and the intermediate binary compounds can form. At a moderate temperature of 500 °C, we find that BaS, associated with fast reaction kinetics, is stable at pressures above 3 × 10 Pa. We also find that BaZrS is stable against decomposition into sulfur-rich binaries up to at least 1 × 10 Pa. Our work provides insights into the chemistry of this promising material and suggests the experimental conditions required for the successful synthesis of BaZrS.
硫族钙钛矿BaZrS具有强烈的可见光吸收能力和高化学稳定性，无毒，且由储量丰富的元素制成。因此，它是光电子技术应用中一种很有前景的候选材料。然而，用于表征和器件集成的BaZrS薄膜的合成仍然是一个挑战。在这里，我们使用密度泛函理论和晶格动力学来计算Ba-Zr-S系统中元素、二元和三元材料的振动特性。这被用于建立一个热力学模型，以研究在一系列温度和硫分压下，BaZrS、BaS和ZrS与硫气相平衡时的稳定性。我们强调反应热力学对硫的同素异形体和同素异形体混合程度高度敏感。我们使用我们的模型来预测BaZrS和中间二元化合物能够形成的合成条件。在500 °C的适中温度下，我们发现与快速反应动力学相关的BaS在压力高于3×10 Pa时是稳定的。我们还发现，在至少1×10 Pa的压力下，BaZrS对分解为富硫二元化合物具有稳定性。我们的工作为这种有前景的材料的化学性质提供了见解，并提出了成功合成BaZrS所需的实验条件。
