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Title: Revealing the biexciton and trion-exciton complexes in BN encapsulated WSe 2

Abstract

Strong Coulomb interactions in single-layer transition metal dichalcogenides (TMDs) result in the emergence of strongly bound excitons, trions, and biexcitons. These excitonic complexes possess the valley degree of freedom, which can be exploited for quantum optoelectronics. However, in contrast to the good understanding of the exciton and trion properties, the binding energy of the biexciton remains elusive, with theoretical calculations and experimental studies reporting discrepant results. In this work, we resolve the conflict by employing low-temperature photoluminescence spectroscopy to identify the biexciton state in BN-encapsulated single-layer WSe 2. The biexciton state only exists in charge-neutral WSe 2, which is realized through the control of efficient electrostatic gating. In the lightly electron-doped WSe 2, one free electron binds to a biexciton and forms the trion–exciton complex. Improved understanding of the biexciton and trion–exciton complexes paves the way for exploiting the many-body physics in TMDs for novel optoelectronics applications.

Authors:
ORCiD logo [1];  [2];  [3]; ORCiD logo [4];  [2];  [5];  [2];  [6];  [6];  [2]; ORCiD logo [7]; ORCiD logo [2]
  1. Rensselaer Polytechnic Inst., Troy, NY (United States); Shanghai Jiao Tong Univ. (China)
  2. Rensselaer Polytechnic Inst., Troy, NY (United States)
  3. Florida State Univ., Tallehassee, FL (United States); National High Magnetic Field Lab. (MagLab), Tallahassee, FL (United States)
  4. Univ. of California, Berkeley, CA (United States)
  5. Rensselaer Polytechnic Inst., Troy, NY (United States); Nanjing Univ. (China)
  6. National Inst. for Materials Science (NIMS), Tsukuba (Japan)
  7. National High Magnetic Field Lab. (MagLab), Tallahassee, FL (United States)
Publication Date:
Research Org.:
Florida State Univ., Tallehassee, FL (United States); Rensselaer Polytechnic Inst., Troy, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1511701
Grant/Contract Number:  
FG02-07ER46451; SC0002623
Resource Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 9; Journal Issue: 1; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Li, Zhipeng, Wang, Tianmeng, Lu, Zhengguang, Jin, Chenhao, Chen, Yanwen, Meng, Yuze, Lian, Zhen, Taniguchi, Takashi, Watanabe, Kenji, Zhang, Shengbai, Smirnov, Dmitry, and Shi, Su-Fei. Revealing the biexciton and trion-exciton complexes in BN encapsulated WSe2. United States: N. p., 2018. Web. doi:10.1038/s41467-018-05863-5.
Li, Zhipeng, Wang, Tianmeng, Lu, Zhengguang, Jin, Chenhao, Chen, Yanwen, Meng, Yuze, Lian, Zhen, Taniguchi, Takashi, Watanabe, Kenji, Zhang, Shengbai, Smirnov, Dmitry, & Shi, Su-Fei. Revealing the biexciton and trion-exciton complexes in BN encapsulated WSe2. United States. doi:10.1038/s41467-018-05863-5.
Li, Zhipeng, Wang, Tianmeng, Lu, Zhengguang, Jin, Chenhao, Chen, Yanwen, Meng, Yuze, Lian, Zhen, Taniguchi, Takashi, Watanabe, Kenji, Zhang, Shengbai, Smirnov, Dmitry, and Shi, Su-Fei. Thu . "Revealing the biexciton and trion-exciton complexes in BN encapsulated WSe2". United States. doi:10.1038/s41467-018-05863-5. https://www.osti.gov/servlets/purl/1511701.
@article{osti_1511701,
title = {Revealing the biexciton and trion-exciton complexes in BN encapsulated WSe2},
author = {Li, Zhipeng and Wang, Tianmeng and Lu, Zhengguang and Jin, Chenhao and Chen, Yanwen and Meng, Yuze and Lian, Zhen and Taniguchi, Takashi and Watanabe, Kenji and Zhang, Shengbai and Smirnov, Dmitry and Shi, Su-Fei},
abstractNote = {Strong Coulomb interactions in single-layer transition metal dichalcogenides (TMDs) result in the emergence of strongly bound excitons, trions, and biexcitons. These excitonic complexes possess the valley degree of freedom, which can be exploited for quantum optoelectronics. However, in contrast to the good understanding of the exciton and trion properties, the binding energy of the biexciton remains elusive, with theoretical calculations and experimental studies reporting discrepant results. In this work, we resolve the conflict by employing low-temperature photoluminescence spectroscopy to identify the biexciton state in BN-encapsulated single-layer WSe2. The biexciton state only exists in charge-neutral WSe2, which is realized through the control of efficient electrostatic gating. In the lightly electron-doped WSe2, one free electron binds to a biexciton and forms the trion–exciton complex. Improved understanding of the biexciton and trion–exciton complexes paves the way for exploiting the many-body physics in TMDs for novel optoelectronics applications.},
doi = {10.1038/s41467-018-05863-5},
journal = {Nature Communications},
number = 1,
volume = 9,
place = {United States},
year = {2018},
month = {9}
}

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Works referenced in this record:

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