Room temperature valley polarization via spin selective charge transfer

• Published in: Nature communications 2023-08, Vol.14 (1), p.5234-5234, Article 5234
• Main Authors: Shrestha, Shreetu, Li, Mingxing, Park, Suji, Tong, Xiao, DiMarzio, Donald, Cotlet, Mircea
• Format: Article
• Language: English
• Subjects: 14/63; 140/125; 140/133; 147/3; 639/301/357/1018; 639/638/440/949; Charge transfer; Crystal structure; Energy; Handedness; Helicity; Heterostructures; Humanities and Social Sciences; Information processing; Information science; Iodides; Lead compounds; Ligands; Linear polarization; Metal halides; Molybdenum; Molybdenum disulfide; multidisciplinary; Perovskites; Photoluminescence; Photons; Polarization; Polarization (spin alignment); Polarized light; Quantum phenomena; Room temperature; Science; Science (multidisciplinary); Spectrum analysis; Symmetry; Temperature; Thin films; Transition metal compounds
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-40967-7

The two degenerate valleys in transition metal dichalcogenides can be used to store and process information for quantum information science and technology. A major challenge is maintaining valley polarization at room temperature where phonon-induced intervalley scattering is prominent. Here we demonstrate room temperature valley polarization in heterostructures of monolayer MoS 2 and naphthylethylammine based one-dimensional chiral lead halide perovskite. By optically exciting the heterostructures with linearly polarized light close to resonance and measuring the helicity resolved photoluminescence, we obtain a degree of polarization of up to −7% and 8% in MoS 2 /right-handed (R-(+)-) and left-handed (S-(-)-) 1-(1-naphthyl)ethylammonium lead iodide perovskite, respectively. We attribute this to spin selective charge transfer from MoS 2 to the chiral perovskites, where the perovskites act as a spin filter due to their chiral nature. Our study provides a simple, yet robust route to obtain room temperature valley polarization, paving the way for practical valleytronics devices. Valleytronics is a portmanteau of ‘valley’ and ‘electronics’ and refers to the use of the valley degree of freedom, present in some materials, for encoding and processing information. Here, Shrestha et al demonstrate a room temperature valley polarization in heterostructures composed of molybdenum disulfide and a chiral lead halide perovskite, an important step in development of valleytronics.