Carmesin Christian, Lorke Michael, Florian Matthias, Erben Daniel, Schulz Alexander, Wehling Tim O, Jahnke Frank
Nano Lett. 2019 May 8;19(5):3182-3186. doi: 10.1021/acs.nanolett.9b00641. Epub 2019 Apr 10.
The observation of quantum light emission from atomically thin transition metal dichalcogenides has opened a new field of applications for these material systems. The corresponding excited charge-carrier localization has been linked to defects and strain, while open questions remain regarding the microscopic origin. We demonstrate that the bending rigidity of these materials leads to wrinkling of the two-dimensional layer. The resulting strain field facilitates strong carrier localization due to its pronounced influence on the band gap. Additionally, we consider charge carrier confinement due to local changes of the dielectric environment and show that both effects contribute to modified electronic states and optical properties. The interplay of surface wrinkling, strain-induced confinement, and local changes of the dielectric environment is demonstrated for the example of nanobubbles that form when monolayers are deposited on substrates or other two-dimensional materials.
对原子级薄的过渡金属二硫属化物的量子光发射的观察为这些材料系统开辟了一个新的应用领域。相应的激发电荷载流子局域化与缺陷和应变有关，而关于微观起源仍存在一些未解决的问题。我们证明，这些材料的弯曲刚度会导致二维层出现褶皱。由于其对带隙有显著影响，由此产生的应变场促进了强载流子局域化。此外，我们考虑了由于介电环境的局部变化导致的电荷载流子限制，并表明这两种效应都有助于改变电子态和光学性质。以单层沉积在衬底或其他二维材料上时形成的纳米气泡为例，展示了表面褶皱、应变诱导限制和介电环境局部变化之间的相互作用。
