Asymmetric valley polarization and photoluminescence in MoS2/MoO3 heterostructure

Shi，Wen Bo1; Jie，H. E.1; Li，Qing Xuan1; She，Xi Chao1; Wang，Di1; Jing，Hao1; Zhang，Rui Li1; Zhao，Jin Zhu2; Peng，Ru Wen1; Hu，X. U.2; Wang，And M.U.1

2019

10.1364/OE.27.038451

Optics Express   影响因子和分区

10944087

1094-4087

We investigate circularly polarized photoluminescence (PL) in the MoS/MoO heterostructure, which was fabricated by transferring MoS monolayer to cover the MoO few layers on the SiO/Si substrate. It is shown that the PL with the same helicity as the excitation light is dominant due to the inherent chiral optical selectivity, which allows exciting one of the valleys in MoS monolayer. The degree of polarization (DP), which characterizes the intensity difference of two chiral components of PL, is unequal for the right-handed and left-handed circularly polarized excitations in the MoS/MoO heterostructure. This effect is different from the one in pristine MoS. Our Raman spectra results together with ab initio calculations indicate the p-doped features of the MoS when it covers the MoO layers. Thus the possible explanation of the unequal DP is that the p-doping process generates a built-in voltage and therefore brings the difference of electron-hole overlaps between K and K' valleys. Namely the asymmetric valley polarization may be obtained in the MoS/MoO heterostructure. Consequently, the circularly polarized PL caused by the electron-hole recombination at K and K' valleys manifests unequal DP for the right-handed and left-handed helix excitations. This asymmetric effect is further enhanced by decreasing the temperature in the MoS/MoO heterostructure. Our investigation provides a unique platform for developing novel two-dimensional valleytronic devices.

SCI ; EI

英语

其他

Key Technologies Research and Development Program[2017YFA0303702] ; Government of Jiangsu Province[BRA2016350] ; National Natural Science Foundation of China[11634005]

Optics

Optics

WOS:000507254300117

OSA - The Optical Society

20200107978512

Calculations ; Circular polarization ; Landforms ; Molybdenum oxide ; Monolayers ; Photoluminescence ; Silica

Geology:481.1 ; Electromagnetic Waves:711 ; Light/Optics:741.1 ; Chemical Products Generally:804 ; Mathematics:921

PHYSICS

2-s2.0-85077266137

Scopus

1.National Laboratory of Solid State Microstructures,School of Physics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing,210093,China
2.Department of Physics and Institute for Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Shi，Wen Bo,Jie，H. E.,Li，Qing Xuan,et al. Asymmetric valley polarization and photoluminescence in MoS2/MoO3 heterostructure[J]. Optics Express,2019,27(26):38451-38462.

Shi，Wen Bo.,Jie，H. E..,Li，Qing Xuan.,She，Xi Chao.,Wang，Di.,...&Wang，And M.U..(2019).Asymmetric valley polarization and photoluminescence in MoS2/MoO3 heterostructure.Optics Express,27(26),38451-38462.

Shi，Wen Bo,et al."Asymmetric valley polarization and photoluminescence in MoS2/MoO3 heterostructure".Optics Express 27.26(2019):38451-38462.