Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2

被引：149

作者：

Cabo, Antonija Grubisic ^{[1
]}

Miwa, Jill A. ^{[1
]}

Gronborg, Signe S. ^{[1
]}

Riley, Jonathon M. ^{[2
]}

Johannsen, Jens C. ^{[3
]}

Cacho, Cephise ^{[4
]}

Alexander, Oliver ^{[4
]}

Chapman, Richard T. ^{[4
]}

Springate, Emma ^{[4
]}

Grioni, Marco ^{[3
]}

Lauritsen, Jeppe V. ^{[1
]}

King, Phil D. C. ^{[2
]}

Hofmann, Philip ^{[1
]}

Ulstrup, Soren ^{[1
]}

机构：

[1] Aarhus Univ, Dept Phys & Astron, Interdisciplinary Nanosci Ctr, DK-8000 Aarhus C, Denmark

[2] Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland

[3] Ecole Polytech Fed Lausanne, Inst Condensed Matter Phys, CH-1015 Lausanne, Switzerland

[4] STFC Rutherford Appleton Lab, Cent Laser Facil, Didcot OX11 0QX, Oxon, England

来源：

NANO LETTERS | 2015年 / 15卷 / 09期

基金：

英国生物技术与生命科学研究理事会; 英国工程与自然科学研究理事会; 瑞士国家科学基金会;

关键词：

Transition metal dichalcogenides; MoS2; free carriers; excitons; time- and angle-resolved photoemission spectroscopy; VALLEY POLARIZATION; EXCITONS; RECOMBINATION; TRANSITION; BANDGAP;

D O I：

10.1021/acs.nanolett.5b01967

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for a SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasipartide band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.

引用

页码：5883 / 5887

页数：5

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