Two-dimensional (2D) transition metal dichalcogenides (TMDs) and perovskites hold substantial promise for various optoelectronic applications such as light emission, photodetection, and energy harvesting. However, each of these materials possesses certain limitations that can be overcome by synergistically combining them to form heterostructures, thereby unveiling intriguing optical properties. In this study, we present an uncomplicated technique for crafting a van der Waals (vdW) heterojunction comprising monolayer WS₂ and a Ruddlesden–Popper (RP) perovskite, namely (TEA)₂PbI₄. By utilizing ultrafast transient absorption (TA) spectroscopy, we explored the charge carrier dynamics within the WS₂/(TEA)₂PbI₄ heterostructure. Our findings uncover a type-II band alignment in the heterostructure, facilitating rapid (within 260 fs) hole transfer from WS₂ to the perovskite and leading to the formation of interlayer excitons (IXs) with a much longer lifetime (728 ps). This strategic approach has the potential to contribute to the development of hybrid systems aimed at achieving high-performance optoelectronic devices.

中文翻译：

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WS2/Ruddlesden-Popper 钙钛矿范德华异质结构中的长寿命层间激子


二维 (2D) 过渡金属二硫属化物 (TMD) 和钙钛矿在光发射、光电检测和能量收集等各种光电应用中具有巨大的前景。然而，这些材料都具有一定的局限性，可以通过将它们协同组合形成异质结构来克服这些局限性，从而揭示有趣的光学特性。在这项研究中，我们提出了一种简单的技术，用于制作由单层 WS ₂ 和 Ruddlesden-Popper (RP) 钙钛矿组成的范德华 (vdW) 异质结，即 (TEA) ₂ PbI ₄ 。通过利用超快瞬态吸收（TA）光谱，我们探索了 WS ₂ /(TEA) ₂ PbI ₄ 异质结构内的载流子动力学。我们的研究结果揭示了异质结构中的 II 型能带排列，促进空穴从 WS ₂ 快速（在 260 fs 内）转移到钙钛矿，并导致形成寿命更长的层间激子 (IX) （728 ps）。这种战略方法有可能有助于开发旨在实现高性能光电器件的混合系统。