Yao Wendian, Yang Dong, Chen Yingying, Hu Junchao, Li Junze, Li Dehui
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Wuhan National Laboratory for Optoelectronics, Optical Valley Laboratory, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Nano Lett. 2022 Sep 14;22(17):7230-7237. doi: 10.1021/acs.nanolett.2c02742. Epub 2022 Aug 29.
Interlayer excitons (IXs) in type II van der Waals (vdW) heterostructures are equipped with an oriented permanent dipole moment and long lifetime and thus would allow promising applications in excitonic and optoelectronic devices. However, based on the widely studied heterostructures of transition-metal dichalcogenides (TMDs), IX emission is greatly influenced by the lattice mismatch and geometric misalignment between the constituent layers, increasing the complexity of the device fabrication. Here, we report on the robust momentum-indirect IX emission in TMD/two-dimensional (2D) perovskite vdW heterostructures, which were fabricated without considering the orientation arrangement or momentum mismatch. The IXs show a large diffusion coefficient of ∼10 cm s, and importantly the IX emission energy can be widely tuned from 1.3 to 1.6 eV via changing the layer number of the 2D perovskite or the thickness of TMD flakes, shedding light on the applications of vdW interface engineering to broad-spectrum optoelectronics.
II型范德华（vdW）异质结构中的层间激子（IXs）具有定向永久偶极矩和长寿命，因此在激子和光电器件中具有广阔的应用前景。然而，基于广泛研究的过渡金属二卤化物（TMDs）异质结构，IX发射受到组成层之间的晶格失配和几何失准的极大影响，增加了器件制造的复杂性。在此，我们报道了TMD/二维（2D）钙钛矿vdW异质结构中稳健的动量间接IX发射，该异质结构的制备无需考虑取向排列或动量失配。IXs显示出约10 cm s的大扩散系数，重要的是，通过改变2D钙钛矿的层数或TMD薄片的厚度，IX发射能量可在1.3至1.6 eV范围内广泛调谐，这为vdW界面工程在广谱光电子学中的应用提供了线索。
