Layer-Number Engineered Momentum-Indirect Interlayer Excitons with Large Spectral Tunability
journal contributionposted on 2022-08-29, 15:05 authored by Wendian Yao, Dong Yang, Yingying Chen, Junchao Hu, Junze Li, Dehui Li
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 cm2 s–1, 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.
∼ 10 cmlarge diffusion coefficientix emission energyindirect ix emissionindirect interlayer excitonsfabricated without consideringvdw interface engineering2 supwidely studied heterostructuresnumber engineered momentumperovskite vdw heterostructureswidely tunedrobust momentummomentum mismatchspectrum optoelectronicsshedding lightorientation arrangementoptoelectronic devicesmetal dichalcogenideslong lifetimelayer numberlattice mismatchgreatly influencedgeometric misalignmentdevice fabricationconstituent layers2d perovskite