Simultaneously Regulated Highly Polarized and Long-Lived Valley Excitons in WSe2/GaN Heterostructures

被引:1
作者
Liu, Haiyang [1 ,2 ]
Zhang, Zongnan [1 ]
Zhang, Chenhao [1 ]
Li, Xu [1 ]
Zhang, Chunmiao [1 ]
Xu, Feiya [1 ]
Wu, Yaping [1 ]
Wu, Zhiming [1 ]
Kang, Junyong [1 ]
机构
[1] Xiamen Univ, Engn Res Ctr Micronano Optoelect Mat & Devices, Fujian Prov Key Lab Semicond Mat & Applicat, Dept Phys,Educ Minist, Xiamen 361005, Peoples R China
[2] Wuhan Univ, Sch Phys Sci & Technol, Wuhan 430072, Peoples R China
基金
中国国家自然科学基金;
关键词
WSe2/GaN heterostructures; twist engineering; interlayer exciton; valley polarization; INTERLAYER EXCITONS; CHARGE-TRANSFER; WAALS; TRANSITION; NANOSHEETS; MONOLAYER; DYNAMICS;
D O I
10.1021/acs.nanolett.3c03494
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Interlayer excitons, with prolonged lifetimes and tunability, hold potential for advanced optoelectronics. Previous research on the interlayer excitons has been dominated by two-dimensional heterostructures. Here, we construct WSe2/GaN composite heterostructures, in which the doping concentration of GaN and the twist angle of bilayer WSe2 are employed as two ingredients for the manipulation of exciton behaviors and polarizations. The exciton energies in monolayer WSe2/GaN can be regulated continuously by the doping levels of the GaN substrate, and a remarkable increase in the valley polarizations is achieved. Especially in a heterostructure with 4 degrees-twisted bilayer WSe2, a maximum polarization of 38.9% with a long lifetime is achieved for the interlayer exciton. Theoretical calculations reveal that the large polarization and long lifetime are attributed to the high exciton binding energy and large spin flipping energy during depolarization in bilayer WSe2/GaN. This work introduces a distinctive member of the interlayer exciton with a high degree of polarization and a long lifetime.
引用
收藏
页码:1851 / 1858
页数:8
相关论文
共 66 条
  • [51] Excitons in 2D heterostructures
    Tartakovskii, Alexander
    [J]. NATURE REVIEWS PHYSICS, 2020, 2 (01) : 8 - 9
  • [52] Valley-polarized exciton currents in a van der Waals heterostructure
    Unuchek, Dmitrii
    Ciarrocchi, Alberto
    Avsar, Ahmet
    Sun, Zhe
    Watanabe, Kenji
    Taniguchi, Takashi
    Kis, Andras
    [J]. NATURE NANOTECHNOLOGY, 2019, 14 (12) : 1104 - +
  • [53] Voiry D, 2013, NAT MATER, V12, P850, DOI [10.1038/nmat3700, 10.1038/NMAT3700]
  • [54] Epitaxial Single-Layer MoS2 on GaN with Enhanced Valley Helicity
    Wan, Yi
    Xiao, Jun
    Li, Jingzhen
    Fang, Xin
    Zhang, Kun
    Fu, Lei
    Li, Pan
    Song, Zhigang
    Zhang, Hui
    Wang, Yilun
    Zhao, Mervin
    Lu, Jing
    Tang, Ning
    Ran, Guangzhao
    Zhang, Xiang
    Ye, Yu
    Dai, Lun
    [J]. ADVANCED MATERIALS, 2018, 30 (05)
  • [55] Wang QH, 2012, NAT NANOTECHNOL, V7, P699, DOI [10.1038/NNANO.2012.193, 10.1038/nnano.2012.193]
  • [56] Excitons and emergent quantum phenomena in stacked 2D semiconductors
    Wilson, Nathan P.
    Yao, Wang
    Shan, Jie
    Xu, Xiaodong
    [J]. NATURE, 2021, 599 (7885) : 383 - 392
  • [57] Xia FN, 2014, NAT PHOTONICS, V8, P899, DOI [10.1038/nphoton.2010.271, 10.1038/nphoton.2014.271]
  • [58] Ye Y, 2016, NAT NANOTECHNOL, V11, P597, DOI [10.1038/nnano.2016.49, 10.1038/NNANO.2016.49]
  • [59] Anomalous Light Cones and Valley Optical Selection Rules of Interlayer Excitons in Twisted Heterobilayers
    Yu, Hongyi
    Wang, Yong
    Tong, Qingjun
    Xu, Xiaodong
    Yao, Wang
    [J]. PHYSICAL REVIEW LETTERS, 2015, 115 (18)
  • [60] Dirac cones and Dirac saddle points of bright excitons in monolayer transition metal dichalcogenides
    Yu, Hongyi
    Liu, Gui-Bin
    Gong, Pu
    Xu, Xiaodong
    Yao, Wang
    [J]. NATURE COMMUNICATIONS, 2014, 5