Probing the Interlayer Exciton Physics in a MoS2/MoSe2/MoS2 van der Waals Heterostructure

被引：131

作者：

Baranowski, M. ^{[1
,2
]}

Surrente, A. ^{[1
]}

Klopotowski, L. ^{[3
]}

Urban, J. M. ^{[1
]}

Zhang, N. ^{[1
]}

Maude, D. K. ^{[1
]}

Wiwatowski, K. ^{[4
]}

Mackowski, S. ^{[4
]}

Kung, Y. C. ^{[5
,6
]}

Dumcenco, D. ^{[5
,6
,7
]}

Kis, A. ^{[5
,6
]}

Plochocka, P. ^{[1
]}

机构：

[1] CNRS UGA UPS INSA, Lab Natl Champs Magnet Intenses, 143 Ave Rangueil, F-31400 Toulouse, France

[2] Wroclaw Univ Sci & Technol, Dept Expt Phys, Fac Fundamental Problems Technol, Wybrzeze Wyspianskiego 27, PL-50370 Wroclaw, Poland

[3] Polish Acad Sci, Inst Phys, Al Lotnikow 32-46, PL-02668 Warsaw, Poland

[4] Nicolaus Copernicus Univ, Fac Phys Astron & Informat, Grudziadzka 5, PL-87100 Torun, Poland

[5] Ecole Polytech Fed Lausanne, Elect Engn Inst, CH-1015 Lausanne, Switzerland

[6] Ecole Polytech Fed Lausanne, Inst Mat Sci & Engn, CH-1015 Lausanne, Switzerland

[7] Univ Geneva, Dept Quantum Matter Phys, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland

来源：

NANO LETTERS | 2017年 / 17卷 / 10期

关键词：

Transition metal dichalcogenides; van der Waals heterostructures; interlayer exciton; chemical vapor deposition; valley polarization; THIN MOS2/WS2 HETEROSTRUCTURES; CHEMICAL-VAPOR-DEPOSITION; 2-DIMENSIONAL MATERIALS; OPTICAL SPECTROSCOPY; CHARGE-TRANSFER; MOSE2/WSE2; MONOLAYERS; DYNAMICS; GROWTH; WSE2;

D O I：

10.1021/acs.nanolett.7b03184

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Stacking atomic monolayers of semiconducting transition metal dichalcogenides (TMDs) has emerged as an effective way to engineer their properties. In principle, the staggered band alignment of TMD heterostructures should result in the formation of interlayer excitons with long lifetimes and robust valley polarization. However, these features have been observed simultaneously only in MoSe2/WSe2 heterostructures. Here we report on the observation of long-lived interlayer exciton emission in a MoS2/MoSe2/MoS2 trilayer van der Waals heterostructure. The interlayer nature of the observed transition is confirmed by photoluminescence spectroscopy, as well as by analyzing the temporal, excitation power, and temperature dependence of the interlayer emission peak. The observed complex photoluminescence dynamics suggests the presence of quasi-degenerate momentum-direct and momentum-indirect bandgaps. We show that circularly polarized optical pumping results in long-lived valley polarization of interlayer exciton. Intriguingly, the interlayer exciton photoluminescence has helicity opposite to the excitation. Our results show that through a careful choice of the TMDs forming the van der Waals heterostructure it is possible to control the circular polarization of the interlayer exciton emission.

引用

页码：6360 / 6365

页数：6

共 46 条

[1] Dark excitons and the elusive valley polarization in transition metal dichalcogenides [J].