Light-matter interactions in high quality manganese-doped two-dimensional molybdenum diselenide

高品質錳摻雜二維二硒化鉬晶體的光與物質相互作用

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Sheng Liu
  • Yaze Wu
  • Xue Liu
  • Andres Granados del Aguila
  • Fengyuan Xuan
  • Apoorva Chaturvedi
  • Su Ying Quek
  • Qihua Xiong

Detail(s)

Original languageEnglish
Pages (from-to)2507-2518
Journal / PublicationScience China Materials
Volume64
Issue number10
Online published8 May 2021
Publication statusPublished - Oct 2021

Abstract

Introducing magnetic dopants into two-dimensional transition metal dichalcogenides has recently attracted considerable attention due to its promising applications in spintronics and valleytronics. Herein we realized manganese-doped molybdenum diselenide (MoSe2) single crystal via chemical vapor transport (CVT) reaction, containing up to 2.9% (atomic concentration) Mn dopants, and investigated the light-matter interaction in these samples. We observed a suppressed trion intensity, a longer photoluminescence lifetime, and prominent blue- and red-shift of E2g2 (in-plane) and A1g (out-of-plane) Raman modes, respectively. Moreover, the Mn dopants increase the valley Zeeman splitting of the MoSe2 monolayer by ∼50%, while preserving the linear dependence on magnetic field. First-principles calculations indicate that the spin-polarized deep level defect states are formed due to the Mn substitutional dopants in the MoSe2 lattice. The resulting defect potential favors the funnelling of excitons towards the defects. The Mn dopants reduce the magnitude of the interatomic force constants, explaining the red-shift of the A1g mode. The Mn atoms and their immediate Mo and Se neighbors carry significant magnetic moments, which enhance the observed exciton g-factors due to the exchange interactions affecting defect-bound excitons.
最近, 將磁性摻雜引入到二維硫族化合物中從而調控自旋電子學及谷電子學的研究引起了科學界的廣泛關注. 本文通過化學氣相轉移生長技術, 實現了二硒化鉬高達2.9%原子豐度的錳摻雜,並採用光譜學技術研究了晶體及解理的少層樣品中光與物質相互作用. 我們發現摻雜抑制了帶電激子的發光, 激子發光具有更長的時間壽命, 同時面內E2g2和麵外A1g聲子振動模式分別呈現出顯著的藍移和紅移. 此外, 錳摻雜增強了能谷塞曼劈裂約50%, 並保持了發光線偏振度對磁場的依賴關係. 第一性原理計算顯示, 錳摻雜替代原子形成自旋極化的深能級, 導致缺陷勢場更傾向於捕獲激子. 錳摻雜降低了原子間的相互作用力常數, 可以解釋面外A1g 聲子振動模式的紅移. 錳原子及最近鄰的鉬和硒原子帶有顯著的磁偶極, 其交換作用影響了缺陷捕獲的激子, 從而增強了實驗中觀察到的g-因子.

Research Area(s)

  • exciton funnelling, first-principles calculations, magnetic doping, two-dimensional semiconductor, valley-Zeeman effect

Citation Format(s)

Light-matter interactions in high quality manganese-doped two-dimensional molybdenum diselenide. / Liu, Sheng; Wu, Yaze; Liu, Xue; del Aguila, Andres Granados; Xuan, Fengyuan; Chaturvedi, Apoorva; Zhang, Hua; Quek, Su Ying; Xiong, Qihua.

In: Science China Materials, Vol. 64, No. 10, 10.2021, p. 2507-2518.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review