TY - JOUR
T1 - Efficient Photocarrier Transfer and Effective Photoluminescence Enhancement in Type I Monolayer MoTe2/WSe2 Heterostructure
AU - Yamaoka, Takao
AU - Lim, Hong En
AU - Koirala, Sandhaya
AU - Wang, Xiaofan
AU - Shinokita, Keisuke
AU - Maruyama, Mina
AU - Okada, Susumu
AU - Miyauchi, Yuhei
AU - Matsuda, Kazunari
N1 - Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/8/29
Y1 - 2018/8/29
N2 - Artificial van der Waals heterostructures of 2D layered materials are attractive from the viewpoint of the possible discovery of new physics together with improved functionalities. Stacking various combinations of atomically thin semiconducting transition metal dichalcogenides, MX2 (M = Mo, W; X = S, Se, Te) with a hexagonal crystal structure, typically leads to the formation of a staggered Type II band alignment in the heterostructure, where electrons and holes are confined in different layers. Here, the comprehensive studies are performed on heterostructures prepared from monolayers of WSe2 and MoTe2 using differential reflectance, photoluminescence (PL), and PL excitation spectroscopy. The MoTe2/WSe2 heterostructure shows strong PL from the MoTe2 layer at ≈1.1 eV, which is different from the quenched PL from the WSe2 layer. Moreover, enhancement of PL intensity from the MoTe2 layer is observed because of the near-unity highly efficient photocarrier transfer from WSe2 to MoTe2. These experimental results suggest that the MoTe2/WSe2 heterostructure has a Type I band alignment where electrons and holes are confined in the MoTe2 layer. The findings extend the diversity and usefulness of ultrathin layered heterostructures based on transition metal dichalcogenides, leading to possibilities toward future optoelectronic applications.
AB - Artificial van der Waals heterostructures of 2D layered materials are attractive from the viewpoint of the possible discovery of new physics together with improved functionalities. Stacking various combinations of atomically thin semiconducting transition metal dichalcogenides, MX2 (M = Mo, W; X = S, Se, Te) with a hexagonal crystal structure, typically leads to the formation of a staggered Type II band alignment in the heterostructure, where electrons and holes are confined in different layers. Here, the comprehensive studies are performed on heterostructures prepared from monolayers of WSe2 and MoTe2 using differential reflectance, photoluminescence (PL), and PL excitation spectroscopy. The MoTe2/WSe2 heterostructure shows strong PL from the MoTe2 layer at ≈1.1 eV, which is different from the quenched PL from the WSe2 layer. Moreover, enhancement of PL intensity from the MoTe2 layer is observed because of the near-unity highly efficient photocarrier transfer from WSe2 to MoTe2. These experimental results suggest that the MoTe2/WSe2 heterostructure has a Type I band alignment where electrons and holes are confined in the MoTe2 layer. The findings extend the diversity and usefulness of ultrathin layered heterostructures based on transition metal dichalcogenides, leading to possibilities toward future optoelectronic applications.
KW - Type I band alignments
KW - photoluminescence
KW - transition metal dichalcogenides
KW - van der Waals heterostructures
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U2 - 10.1002/adfm.201801021
DO - 10.1002/adfm.201801021
M3 - Article
AN - SCOPUS:85050915529
SN - 1616-301X
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 35
M1 - 1801021
ER -