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Title: Synthetic WSe 2 monolayers with high photoluminescence quantum yield

Abstract

In recent years, there have been tremendous advancements in the growth of monolayer transition metal dichalcogenides (TMDCs) by chemical vapor deposition (CVD). However, obtaining high photoluminescence quantum yield (PL QY), which is the key figure of merit for optoelectronics, is still challenging in the grown monolayers. Specifically, the as-grown monolayers often exhibit lower PL QY than their mechanically exfoliated counterparts. In this work, we demonstrate synthetic tungsten diselenide (WSe 2) monolayers with PL QY exceeding that of exfoliated crystals by over an order of magnitude. PL QY of ~60% is obtained in monolayer films grown by CVD, which is the highest reported value to date for WSe 2 prepared by any technique. The high optoelectronic quality is enabled by the combination of optimizing growth conditions via tuning the halide promoter ratio, and introducing a simple substrate decoupling method via solvent evaporation, which also mechanically relaxes the grown films. The achievement of scalable WSe 2 with high PL QY could potentially enable the emergence of technologically relevant devices at the atomically thin limit.

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1];  [1];  [2];  [2];  [1];  [1]; ORCiD logo [2]; ORCiD logo [2];  [2]; ORCiD logo [1]
  1. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1560585
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Science Advances
Additional Journal Information:
Journal Volume: 5; Journal Issue: 1; Journal ID: ISSN 2375-2548
Publisher:
AAAS
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Kim, Hyungjin, Ahn, Geun Ho, Cho, Joy, Amani, Matin, Mastandrea, James P., Groschner, Catherine K., Lien, Der-Hsien, Zhao, Yingbo, Ager, Joel W., Scott, Mary C., Chrzan, Daryl C., and Javey, Ali. Synthetic WSe2 monolayers with high photoluminescence quantum yield. United States: N. p., 2019. Web. doi:10.1126/sciadv.aau4728.
Kim, Hyungjin, Ahn, Geun Ho, Cho, Joy, Amani, Matin, Mastandrea, James P., Groschner, Catherine K., Lien, Der-Hsien, Zhao, Yingbo, Ager, Joel W., Scott, Mary C., Chrzan, Daryl C., & Javey, Ali. Synthetic WSe2 monolayers with high photoluminescence quantum yield. United States. https://doi.org/10.1126/sciadv.aau4728
Kim, Hyungjin, Ahn, Geun Ho, Cho, Joy, Amani, Matin, Mastandrea, James P., Groschner, Catherine K., Lien, Der-Hsien, Zhao, Yingbo, Ager, Joel W., Scott, Mary C., Chrzan, Daryl C., and Javey, Ali. Wed . "Synthetic WSe2 monolayers with high photoluminescence quantum yield". United States. https://doi.org/10.1126/sciadv.aau4728. https://www.osti.gov/servlets/purl/1560585.
@article{osti_1560585,
title = {Synthetic WSe2 monolayers with high photoluminescence quantum yield},
author = {Kim, Hyungjin and Ahn, Geun Ho and Cho, Joy and Amani, Matin and Mastandrea, James P. and Groschner, Catherine K. and Lien, Der-Hsien and Zhao, Yingbo and Ager, Joel W. and Scott, Mary C. and Chrzan, Daryl C. and Javey, Ali},
abstractNote = {In recent years, there have been tremendous advancements in the growth of monolayer transition metal dichalcogenides (TMDCs) by chemical vapor deposition (CVD). However, obtaining high photoluminescence quantum yield (PL QY), which is the key figure of merit for optoelectronics, is still challenging in the grown monolayers. Specifically, the as-grown monolayers often exhibit lower PL QY than their mechanically exfoliated counterparts. In this work, we demonstrate synthetic tungsten diselenide (WSe2) monolayers with PL QY exceeding that of exfoliated crystals by over an order of magnitude. PL QY of ~60% is obtained in monolayer films grown by CVD, which is the highest reported value to date for WSe2 prepared by any technique. The high optoelectronic quality is enabled by the combination of optimizing growth conditions via tuning the halide promoter ratio, and introducing a simple substrate decoupling method via solvent evaporation, which also mechanically relaxes the grown films. The achievement of scalable WSe2 with high PL QY could potentially enable the emergence of technologically relevant devices at the atomically thin limit.},
doi = {10.1126/sciadv.aau4728},
url = {https://www.osti.gov/biblio/1560585}, journal = {Science Advances},
issn = {2375-2548},
number = 1,
volume = 5,
place = {United States},
year = {2019},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 14 works
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Figures / Tables:

Fig. 1 Fig. 1: Synthetic WSe2 monolayer with high PL QY after SEMD. ( A) Schematic of the SEMD process. An as-grown WSe 2 monolayer is immersed in a droplet of solvent. During the solvent evaporation, the substrate decoupling process of the WSe 2 monolayer is accomplished with the enhanced PL QY.more » ( B) PL spectra measured at the center of an as-grown WSe 2 monolayer with an excitation power of 15 W cm −2 before and after the SEMD process; inset shows normalized spectra. ( C to G) In situ PL imaging of the SEMD process in a WSe 2 monolayer. Scale bars, 30 μm (for all PL images). Note that the images were taken using a 1.65-eV bandpass filter that blocks the emission from the as-grown monolayer and plotted on a logarithmic scale. PL intensity profile across the WSe 2 monolayer is presented in the bottom plots. PL images at additional timestamps are shown in fig. S1. a.u., arbitrary units. ( H) Overlay of diffraction spots for as-grown and substrate-decoupled samples; 1.54 ± 0.05% tensile strain in the as-grown sample is released after the SEMD process. Scale bar, 5 nm −1. Original diffraction patterns of the samples are shown in fig. S5. ( I) Schematic describing the factors influencing the SEMD process of the WSe 2 monolayer.« less

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    Centimeter‐Scale and Visible Wavelength Monolayer Light‐Emitting Devices
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    Chemically Tuned p‐ and n‐Type WSe 2 Monolayers with High Carrier Mobility for Advanced Electronics
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    Wafer-scale and deterministic patterned growth of monolayer MoS 2 via vapor–liquid–solid method
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    Ni–WSe 2 nanostructures as efficient catalysts for electrochemical hydrogen evolution reaction (HER) in acidic and alkaline media
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    Collective excitations in 2D atomic layers: Recent perspectives
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    Enhancing monolayer photoluminescence on optical micro/nanofibers for low-threshold lasing
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    Enhancing functionalities of atomically thin semiconductors with plasmonic nanostructures
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      Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.