Excited-State Trions in Monolayer WS2

被引：66

作者：

Arora, Ashish ^{[1
,2
]}

Deilmann, Thorsten ^{[3
]}

Reichenauer, Till ^{[1
,2
]}

Kern, Johannes ^{[1
,2
]}

de Vasconcellos, Steffen Michaelis ^{[1
,2
]}

Rohlfing, Michael ^{[3
]}

Bratschitsch, Rudolf ^{[1
,2
]}

机构：

[1] Univ Munster, Inst Phys, Wilhelm Klemm Str 10, D-48149 Munster, Germany

[2] Univ Munster, Ctr Nanotechnol, Wilhelm Klemm Str 10, D-48149 Munster, Germany

[3] Univ Munster, Inst Solid State Theory, Wilhelm Klemm Str 10, D-48149 Munster, Germany

来源：

PHYSICAL REVIEW LETTERS | 2019年 / 123卷 / 16期

关键词：

NEGATIVELY CHARGED EXCITONS; OPTICAL-TRANSITIONS; GREENS-FUNCTION; QUANTUM; EXCITATIONS; ABSORPTION; SPECTRA; DENSITY; ION;

D O I：

10.1103/PhysRevLett.123.167401

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We discover an excited bound three-particle state, the 2s trion, appearing energetically below the 2s exciton in monolayer WS2, using absorption spectroscopy and ab initio GW and Bethe-Salpeter equation calculations. The measured binding energy of the 2s trion (22 meV) is smaller compared to the 1s intravalley and intervalley trions (37 and 31 meV). With increasing temperature, the 1s and 2s trions transfer their oscillator strengths to the respective neutral excitons, establishing an optical fingerprint of trion-exciton resonance pairs. Our discovery underlines the importance of trions for the entire excitation spectrum of two-dimensional semiconductors.

引用

页数：6