The perovskite structure provides a versatile framework for functional materials and their high-quality heteroepitaxial interfaces. Perovskite halides (PH) have attracted intense interest for their application in optoelectronics. Oxides are another major class of perovskites that are widely used in fuel cells, nonconventional electronics and electrochemistry. Interfacing different perovskite oxides (POs) has led to a multitude of fascinating discoveries. By introducing anionic degree of freedom, we expect that perovskite hetero-anionic-sublattice interfaces can provide a new platform for emergent phenomena that may or may not have homo-oxygen-sublattice interface analogues. In this work, we investigate the interfaces between the all-inorganic PH CsPbBr₃, the emerging double perovskite halide (dPH) Cs₂TiBr₆ and various common POs. Based on the band alignment properties, these POs are considered to be suitable carrier transport materials (CTMs) for CsPbBr₃ and Cs₂TiBr₆ in either light-harvesting or light-emitting devices. In addition, these perovskite hetero-anionic-sublattice interfaces are found to be defect- and dangling bond-free due to compatible crystal lattices, making POs potentially outperform conventional binary transition-metal–oxide and organic CTMs. Besides optoelectronics, the potential of perovskite hetero-anionic-sublattice interfaces for nonconventional electronics is also explored. As examples, two-dimensionally confined electron–hole systems are predicted at the asymmetric interfaces in both Cs₂TiBr₆:LaAlO₃ and CsPbBr₃:LaAlO₃ superlattice structures. This finding, along with the optically active properties of PHs, may spark novel applications of light–electron interaction in perovskite systems. This work presents new opportunities for perovskite heteroepitaxial interfaces.

中文翻译：

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光电和非常规电子的钙钛矿杂阴离子-亚晶格界面

钙钛矿结构为功能材料及其高质量异质外延界面提供了通用框架。钙钛矿卤化物（PH）在光电子学中的应用引起了人们极大的兴趣。氧化物是钙钛矿的另一大类，广泛用于燃料电池，非常规电子学和电化学中。连接不同的钙钛矿氧化物（POs）导致了许多有趣的发现。通过引入阴离子自由度，我们期望钙钛矿杂阴离子-亚晶格界面可以为可能具有或没有均氧-亚晶格界面类似物的新兴现象提供一个新的平台。在这项工作中，我们研究了全无机PH CsPbBr ₃与新兴的双钙钛矿卤化物（dPH）Cs之间的界面₂ TiBr ₆和各种常见的PO。基于能带对齐特性，这些PO被认为是光收集或发光设备中CsPbBr ₃和Cs ₂ TiBr _6的合适载流子传输材料（CTM）。此外，由于兼容的晶格，这些钙钛矿杂-阴离子-亚晶格界面被发现没有缺陷和悬空键，使POs可能优于传统的二元过渡金属氧化物和有机CTM。除光电子学外，还探索了钙钛矿杂阴离子-亚晶格界面在非常规电子学中的潜力。例如，在两个Cs的不对称界面处都将预测二维约束电子-空穴系统₂ TiBr ₆：LaAlO ₃和CsPbBr ₃：LaAlO ₃超晶格结构。这一发现以及PH的光学活性可能会激发钙钛矿体系中光电子相互作用的新应用。这项工作为钙钛矿异质外延界面提供了新的机会。