Giant Light Emission Enhancement in Strain-Engineered InSe/MS<sub>2</sub> (M = Mo or W) van der Waals Heterostructures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39908056.
- Also identified by DOI 10.1021/acs.nanolett.4c04252 and PMC identifier 11887447.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Two-dimensional (2D) heterostructures (HSs) offer unlimited possibilities for playing with layer number, order, and twist angle. The realization of high-performance optoelectronic devices, however, requires the achievement of specific band alignments, <i>k</i>-space matching between conduction and valence band extrema, and efficient charge transfer between the constituent layers. Fine-tuning mechanisms to design ideal HSs are lacking. Here, we show that layer-selective strain engineering can be exploited as an extra degree of freedom to tailor the band alignment and optical properties of 2D HSs. To that end, strain is selectively applied to MS<sub>2</sub> (M = Mo or W) monolayers in InSe/MS<sub>2</sub> HSs, triggering a giant photoluminescence enhancement of the highly tunable but weakly emitting InSe of up to >2 orders of magnitude. Resonant excitation measurements, supported by first-principles calculations, provide evidence of a strain-activated charge transfer from the MS<sub>2</sub> monolayers toward InSe. The huge emission enhancement of InSe widens its range of applications for optoelectronics.