Chiral molecule induced valley polarization enhancement of MoS₂

Abstract

Monolayers of transition metal dichalcogenides (TMDCs) are atomically thin direct-bandgap semiconductors with potential applications in nanoelectronics, opto-electronics, and electrochemical sensing. Recent theoretical and experimental results have suggested that they are...

Optically Addressing Exciton Spin and Pseudospin in Nanomaterials for Spintronics Applications

“…Even linear polarization impingent on the nanostructures transduces a valley polarization difference in MoS 2 . Similary, enhanced valley contrast was reported by depositing chiral molecules directly on MoS 2 . Other recent advances suggest that some of the polarization selectivity of charge transfer upon photoexcitation is instrinsic to the chiral nature of the molecules used in the perovskite structure, and not necessarily created by the light source .…”

“…Similary, enhanced valley contrast was reported by depositing chiral molecules directly on MoS 2 . 136 Other recent advances suggest that some of the polarization selectivity of charge transfer upon photoexcitation is instrinsic to the chiral nature of the molecules used in the perovskite structure, and not necessarily created by the light source. 137 Although this general phenomenon of chirality induced spin selectivity (CISS) has promise in fields adjacent to the subject of this review, 138 for purposes of fast optical modulation of spin behavior and associated magnetism the relatively fixed nature of chiral sense makes these architectures less relevant.…”

Chiral Induced Spin Selectivity

“…Research on single monolayer MoS 2 and WSe 2 interfaced with chiral perovskites showed changes in the degree of valley polarization and the effect was attributed to the spin-selective charge injection from the chiral perovskite, i.e., CISS . A similar enhancement in valley polarization was also observed when d -histidine was interfaced with a monolayer of MoS 2 . Here, the spin-dependent charge redistribution properties of the histidine, and strong hybridization between histidine and the MoS 2 , led to the degree of polarization at the + K valley being 7.73% and the − K valley being 1.6%.…”

“…177 A similar enhancement in valley polarization was also observed when D-histidine was interfaced with a monolayer of MoS 2 . 186 Here, the spin-dependent charge redistribution properties of the histidine, and strong hybridization between histidine and the MoS 2 , led to the degree of polarization at the +K valley being 7.73% and the −K valley being 1.6%. Note that spin-dependent charge redistributions in chiral molecules can lead to spontaneous magnetization, 20 and application of external magnetic fields to TMDs can cause a Zeeman energy splitting that increases valley contrast.…”