自陷获能实现高亮度动量间接层间激子

中文摘要 AI 辅助

二维材料异质结构中的层间激子具有大的激子结合能和长寿命，使其成为研究激子器件和多体量子现象的理想平台。然而，层间激子（IX）中空间分离的电子和空穴特性使其振子强度比层内激子低两个数量级。实现高效的层间激子发射仍然具有挑战性，需要选择具有适当动量匹配的最佳材料并进行精密的器件制造。在此，我们展示了在二维钙钛矿与单层过渡金属二硫化物（TMD）形成的异质结构中，实现了高亮度的动量间接层间激子发射。层间激子发射的量子产率平均达到35.2%，比相应组成TMD单层的量子产率高50倍以上，最高值超过60%。值得注意的是，这种动量间接层间激子的辐射复合效率比基于单层TMD异质结构中的动量直接层间激子高两个数量级。我们认为，我们异质结构中异常明亮的层间激子发射源于层间激子自陷获，这是由二维钙钛矿软晶格特性引起的强激子-声子耦合所诱导的。我们的发现为实现高层间激子发射效率提供了新的见解，并为探索长寿命激子器件开辟了新途径。

英文摘要

Interlayer excitons in two dimensional material heterostructures exhibit large exciton binding energies and long lifetimes, making them ideal platforms for studying excitonic devices and many body quantum phenomena. However, the spatially separated electron and hole nature of IXs reduces their oscillator strength by two orders of magnitude compared to intralayer excitons. Achieving high efficiency IX emission remains challenging and requires optimal material selection with appropriate momentum matching and meticulous device fabrication. Here we demonstrate a highly bright momentum indirect IX emission within heterostructures formed between 2D perovskites and monolayer transition metal dichalcogenides. The quantum yield of IX emission reaches 35.2% on average, over 50 times higher than that of the corresponding constituent TMD monolayer, with the highest value exceeding 60%. Notably, the radiative recombination efficiency of this momentum indirect IX exceeds that of momentum direct IXs in monolayer TMD-based heterostructures by two orders of magnitude. We suggest that the remarkably bright IX emission in our heterostructure originates from IX self trapping, induced by strong exciton phonon coupling arising from the soft lattice nature of the 2D perovskite. Our findings provide new insights into achieving high IX emission efficiency and open new avenues for exploring long lifetime excitonic devices.

发表机构

• Huazhong University of Science and Technology（华中科技大学）
• Tsinghua University（清华大学）
• Nanyang Technological University（南洋理工大学）
• Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）

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