Title: Twist Angle-Dependent Interlayer Exciton Lifetimes in van der Waals Heterostructures

Abstract

In van der Waals (vdW) heterostructures formed by stacking two monolayers of transition metal dichalcogenides, multiple exciton resonances with highly tunable properties are formed and subject to both vertical and lateral confinement. We investigate how a unique control knob, the twist angle between the two monolayers, can be used to control the exciton dynamics. We observe that the interlayer exciton lifetimes in MoSe₂/WSe₂ twisted bilayers (TBLs) change by one order of magnitude when the twist angle is varied from 1° to 3.5°. Additionally, using a low-energy continuum model, we theoretically separate two leading mechanisms that influence interlayer exciton radiative lifetimes. The shift to indirect transitions in the momentum space with an increasing twist angle and the energy modulation from the moiré potential both have a significant impact on interlayer exciton lifetimes. We further predict distinct temperature dependence of interlayer exciton lifetimes in TBLs with different twist angles, which is partially validated by experiments. While many recent studies have highlighted how the twist angle in a vdW TBL can be used to engineer the ground states and quantum phases due to many-body interaction, our studies explore its role in controlling the dynamics of optically excited states, thus, expanding the conceptual applicationsmore » of “twistronics”.« less

Authors:

Choi, Junho  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-8740-650X"

Florian, Matthias ^[2]; Steinhoff, Alexander ^[2]; Erben, Daniel  ^[2];

• Search DOE PAGES for author "Erben, Daniel"
• Search DOE PAGES for ORCID "0000-0003-3921-3137"

Tran, Kha ^[1]; Kim, Dong Seob ^[1]; Sun, Liuyang ^[1]; Quan, Jiamin ^[1]; Claassen, Robert  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-8482-0457"

Majumder, Somak  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-1052-0627"

Hollingsworth, Jennifer A. ^[3]; Taniguchi, Takashi ^[4]; Watanabe, Kenji ^[4]; Ueno, Keiji  ^[5];

• Search DOE PAGES for author "Ueno, Keiji"
• Search DOE PAGES for ORCID "0000-0002-5535-9382"

Singh, Akshay  ^[6];

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• Search DOE PAGES for ORCID "0000-0003-1059-065X"

Moody, Galan ^[7]; Jahnke, Frank ^[2]; Li, Xiaoqin ^[1]

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+ Show Author Affiliations

1. Univ. of Texas, Austin, TX (United States)
2. Univ. of Bremen (Germany)
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies (CINT)
4. National Inst. for Materials Science, Ibaraki (Japan)
5. Saitama Univ. (Japan)
6. Indian Inst. of Science, Bengaluru (India)
7. Univ. of California, Santa Barbara, CA (United States)

Publication Date:

Tue Jan 26 00:00:00 EST 2021

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Science Foundation (NSF); Japan MEXT; JSPS KAKENHI; Welch Foundation; German Research Foundation (DFG)

OSTI Identifier:

1859894

Alternate Identifier(s):

OSTI ID: 1764224

Report Number(s):

LA-UR-20-28297; LA-UR-20-28296
Journal ID: ISSN 0031-9007; TRN: US2305367

Grant/Contract Number:  

89233218CNA000001; DMR-1808042; DMR-1720595; F-1662; EFMA-1542747; JPMXP0112101001; JP20H00354; 25107004; M61500295; DMR-1906325; RTG 2247

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Letters

Additional Journal Information:

Journal Volume: 126; Journal Issue: 4; Journal ID: ISSN 0031-9007

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; excitons; quantum wells; semiconductor compounds; transition-metal dichalcogenide; photoluminescence; Material Science