Light‐emitting diodes (LEDs) have revolutionized lighting and displays due to their numerous advantages over conventional lighting mechanisms. Moreover, the directional nature of luminescent materials has spurred significant advancements in the development of circularly polarized LEDs, which hold transformative potential for applications in biomedical imaging, liquid crystal displays, spintronics, and valleytronics. The performance of circularly polarized LEDs mainly depends on the emitter material, which is this study's focus. In particular, semiconducting‐phase 2D monolayer MoS2 and WS2 are attractive emitter‐material candidates owing to their bandgap versatility, high carrier mobility, high exciton binding energy, polarized‐light‐emission properties, and unique spin–valley coupling. Several works have examined the fundamental light‐emission properties of monolayer MoS2 and WS2 from the perspectives of optoelectronic concepts, material fabrication, and device construction. This paper presents approaches to control, tune, and enhance these properties of monolayer MoS2 and WS2. Possible guidelines for monolayer‐material synthesis (top‐down and bottom‐up approaches) and device engineering of vertically stacked MoS2 and WS2 are presented. Finally, the review considers the material topological characteristics, outlines the challenges and potential of monolayer MoS2 and WS2 for developing high‐performance commercial circularly polarized LED devices, and proposes a technological roadmap for leveraging other monolayer transition metal dichalcogenide systems in optoelectronic devices.

中文翻译：

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用于垂直圆偏振发光二极管的单层 MoS2 和 WS2：从基本理解到器件架构


发光二极管 （LED） 与传统照明机制相比具有众多优势，因此彻底改变了照明和显示器。此外，发光材料的定向特性推动了圆偏振 LED 的开发取得重大进展，这在生物医学成像、液晶显示器、自旋电子学和谷电子学中的应用具有变革性的潜力。圆极化 LED 的性能主要取决于发射器材料，这是本研究的重点。特别是，半导体相 2D 单层 MoS2 和 WS2 是有吸引力的发射极材料候选者，因为它们具有带隙多功能性、高载流子迁移率、高激子结合能、偏振光发射特性和独特的自旋谷耦合。一些工作从光电概念、材料制造和器件构建的角度研究了单层 MoS2 和 WS2 的基本发光特性。本文提出了控制、调整和增强单层 MoS2 和 WS2 的这些特性的方法。提出了垂直堆叠 MoS2 和 WS2 的单层材料合成（自上而下和自下而上方法）和器件工程的可能指南。最后，综述考虑了材料拓扑特性，概述了单层 MoS2 和 WS2 在开发高性能商用圆极化 LED 器件方面的挑战和潜力，并提出了在光电器件中利用其他单层过渡金属硫化物系统的技术路线图。