Room temperature near unity spin polarization in 2D Van der Waals heterostructures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32895376.
- Also identified by DOI 10.1038/s41467-020-18307-w and PMC identifier 7477097.
- 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
The generation and manipulation of spin polarization at room temperature are essential for 2D van der Waals (vdW) materials-based spin-photonic and spintronic applications. However, most of the high degree polarization is achieved at cryogenic temperatures, where the spin-valley polarization lifetime is increased. Here, we report on room temperature high-spin polarization in 2D layers by reducing its carrier lifetime via the construction of vdW heterostructures. A near unity degree of polarization is observed in PbI<sub>2</sub> layers with the formation of type-I and type-II band aligned vdW heterostructures with monolayer WS<sub>2</sub> and WSe<sub>2</sub>. We demonstrate that the spin polarization is related to the carrier lifetime and can be manipulated by the layer thickness, temperature, and excitation wavelength. We further elucidate the carrier dynamics and measure the polarization lifetime in these heterostructures. Our work provides a promising approach to achieve room temperature high-spin polarizations, which contribute to spin-photonics applications.