Following the rapid development of information technology, modern polarized light, which is a critical component for display and data transmission, has been in demand for miniaturization and high efficiency, rendering two‐dimensional (2D) semiconductors potential candidates. The traditional polarized light is usually generated by external optical structures or polarizers that influence the scaling and bring up losses. Previous works have reported polarized light emission from inversion‐asymmetric 2D semiconductors such as black phosphorus (BP), black arsenide phosphorus (AsP), and rhenium disulfide (ReS2), however, their emission wavelengths are not in the visible range. Here, a direct emission of linearly polarized light is demonstrated from van der Waals light–emitting diodes (vdWLEDs) via the flexoelectric effects by inducing the non‐uniform strain in monolayer (ML) transition metal dichalcogenides (TMDCs). In this work, the effects of strain including excitonic binding energy and exciton dipole moment distribution is analyzed by the density functional theory (DFT) then we show that linearly polarized photoluminescence (PL) with a degree of linear polarization (DOLP) of ≈17% can be realized at room temperature (RT), and the polarization angle is perpendicular to the direction of the strain‐gradient. By incorporating the strained ML TMDCs into vdWLEDs, electroluminescence (EL) with DOLP of ≈19% can be observed at RT. This work puts forward a direct and universal strategy for fabricating polarized LEDs based on inversion‐symmetric semiconductors.

中文翻译：

---

通过挠曲电效应在范德华 LED 中直接线性极化发射


随着信息技术的快速发展，作为显示和数据传输关键部件的现代偏振光对小型化和高效率的需求越来越大，使二维 （2D） 半导体成为潜在的候选者。传统的偏振光通常由外部光学结构或偏振器产生，这些结构或偏振器会影响缩放并产生损耗。以前的工作报道了黑磷 （BP）、黑砷化磷 （AsP） 和二硫化铼 （ReS2） 等反转不对称二维半导体的偏振光发射，但是，它们的发射波长不在可见光范围内。在这里，范德华发光二极管 （vdWLED） 通过在单层 （ML） 过渡金属硫化物 （TMDC） 中诱导非均匀应变，通过挠曲电效应证明了线性偏振光的直接发射。在这项工作中，通过密度泛函理论 （DFT） 分析了包括激子结合能和激子偶极矩分布在内的应变的影响，然后我们证明在室温 （RT） 下可以实现线性偏振度 （DOLP） 为 ≈17% 的线偏振光致发光 （PL），并且偏振角垂直于应变梯度的方向。通过将应变的 ML TMDC 掺入 vdWLED 中，可以在 RT 下观察到 DOLP 为 ≈19% 的电致发光 （EL）。这项工作提出了一种基于反转对称半导体制造偏振 LED 的直接和通用策略。