TY - JOUR
T1 - Vertical Heterophase for Electrical, Electrochemical, and Mechanical Manipulations of Layered MoTe2
AU - Eshete, Yonas Assefa
AU - Ling, Ning
AU - Kim, Sera
AU - Kim, Dohyun
AU - Hwang, Geunwoo
AU - Cho, Suyeon
AU - Yang, Heejun
N1 - Funding Information:
This work was supported by the Samsung Research Funding and Incubation Center of Samsung Electronics under Project No. SRFC-MA1701-01. S.C. was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, Information Communication Technology (ICT) and Future Planning (2017R1A2B4010423).
Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Phase engineering is a breakthrough for various electronic and energy device applications with transition metal dichalcogenides (TMDs). Chemical methods, such as lithium intercalation, are mostly used for phase engineering, which achieves atomically thin flakes and high catalytic performances in several group 6 TMDs including MoS2. However, chemical methods cannot be applied to MoTe2, a widely investigated group 6 TMD with intriguing semiconducting, topological, and catalytic properties. The lack of modifying MoTe2 by chemical methods remains a puzzling issue considering the small energy difference between the polymorphs of MoTe2. Here, a convection-assisted lithium ion intercalation and phase transition is reported to achieve a vertical heterophase in a MoTe2 crystal. The vertical heterophase in MoTe2 reduces the Schottky barrier with metal electrodes down to 66 meV, enhancing the overall ion conductance for electrochemical hydrogen production. Moreover, the weakened adhesion of the 1T' phase layers on the top and bottom surfaces in the vertical heterophase, formed by the intercalation, enables a unique surface tension-driven exfoliation of MoTe2 flakes. The heterophase chemical engineering suggests a new platform for hybrid catalysts and next-generation electronic devices based on 2D materials.
AB - Phase engineering is a breakthrough for various electronic and energy device applications with transition metal dichalcogenides (TMDs). Chemical methods, such as lithium intercalation, are mostly used for phase engineering, which achieves atomically thin flakes and high catalytic performances in several group 6 TMDs including MoS2. However, chemical methods cannot be applied to MoTe2, a widely investigated group 6 TMD with intriguing semiconducting, topological, and catalytic properties. The lack of modifying MoTe2 by chemical methods remains a puzzling issue considering the small energy difference between the polymorphs of MoTe2. Here, a convection-assisted lithium ion intercalation and phase transition is reported to achieve a vertical heterophase in a MoTe2 crystal. The vertical heterophase in MoTe2 reduces the Schottky barrier with metal electrodes down to 66 meV, enhancing the overall ion conductance for electrochemical hydrogen production. Moreover, the weakened adhesion of the 1T' phase layers on the top and bottom surfaces in the vertical heterophase, formed by the intercalation, enables a unique surface tension-driven exfoliation of MoTe2 flakes. The heterophase chemical engineering suggests a new platform for hybrid catalysts and next-generation electronic devices based on 2D materials.
KW - chemical intercalation
KW - convection
KW - exfoliation
KW - hydrogen evolution reaction
KW - phase transition
KW - Schottky barrier height
UR - http://www.scopus.com/inward/record.url?scp=85070526803&partnerID=8YFLogxK
U2 - 10.1002/adfm.201904504
DO - 10.1002/adfm.201904504
M3 - Article
AN - SCOPUS:85070526803
VL - 29
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 40
M1 - 1904504
ER -