MoS$_2$ flake as a van der Waals homostructure: luminescence properties and optical anisotropy

Low-temperature photoluminescence of oxide-covered single-layer MoS2

We present a photoluminescence study of single-layer MoS2 flakes on SiO2 surfaces. We demonstrate that the luminescence peak position of flakes prepared from natural MoS2, which varies by up to 25 meV between individual as-prepared flakes, can be homogenized by annealing in vacuum, which removes adsorbates from the surface. We use HfO2 and Al2O3 layers prepared by atomic layer deposition to cover some of our flakes. We clearly observe a suppression of the low-energy luminescence peak observed for as-prepared flakes at low temperatures, indicating that this peak originates from excitons bound t…

在通信波长具有室温光子发射的铒注入 WS2 薄片

Erbium-implanted WS2 flakes with room-temperature photon emission at telecom wavelengths

本文通过离子注入、共聚焦显微和第一性原理计算研究掺铒 WS2 薄片，实现经低温退火激活、通信波段窄线宽且温度稳定的长寿命光致发光。

原子级分辨范德华异质结构的针尖诱导激子发光纳米成像

Tip-induced excitonic luminescence nanoscopy of an atomically-resolved van der Waals heterostructure

利用低温扫描隧道显微镜以原子级分辨率探测范德华异质结构的本征发光，揭示了激子发射随纳米环境变化的规律，为原子尺度理解与控制莫尔超晶格光电现象奠定基础。

Spectrally narrow exciton luminescence from monolayer MoS2 exfoliated onto epitaxially grown hexagonal BN

The strong light-matter interaction in transition Metal dichalcogenides (TMDs) monolayers (MLs) is governed by robust excitons. Important progress has been made to control the dielectric environment surrounding the MLs, especially through hexagonal boron nitride (hBN) encapsulation, which drastically reduces the inhomogeneous contribution to the exciton linewidth. Most studies use exfoliated hBN from high quality flakes grown under high pressure. In this work, we show that hBN grown by molecular beam epitaxy (MBE) over a large surface area substrate has a similarly positive impact on the optic…

Hybrid electroluminescent devices composed of (In,Ga)N micro-LEDs and monolayers of transition metal dichalcogenides

We demonstrate a novel electro-luminescence device in which GaN-based $μ$-LEDs are used to trigger the emission spectra of monolayers of transition metal dichalcogenides, which are deposited directly on the $μ$-LED surface. A special $μ$-LED design enables the operation of our structures even in the limit of low temperatures. A device equipped with a selected WSe$_2$ monolayer flake is shown to act as a stand-alone, electrically-driven single-photon source.

黑磷层发光中的量子阱限制与竞争性辐射路径

Quantum well confinement and competitive radiative pathways in the luminescence of black phosphorus layers

本文通过4 K下测量79片4–700 nm钝化BP薄片的光致发光，揭示剥离缺陷引入的竞争辐射通道，并用25 nm以上显现的量子阱限制模型解释能量随厚度演化。