Premium
Extraordinary Temperature Dependent Second Harmonic Generation in Atomically Thin Layers of Transition‐Metal Dichalcogenides
Author(s) -
Khan Ahmed Raza,
Liu Boqing,
Zhang Linglong,
Zhu Yi,
He Xin,
Zhang Lijun,
Lü Tieyu,
Lu Yuerui
Publication year - 2020
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202000441
Subject(s) - materials science , second harmonic generation , transition metal , thin film , thermal expansion , optoelectronics , laser , condensed matter physics , nanotechnology , optics , biochemistry , chemistry , physics , catalysis , metallurgy
Atomically thin transition metal dichalcogenides (TMDs) are important semiconducting materials because of their interesting layer dependent properties. Recently, optical second harmonic generation (SHG) is used to probe layer number, lattice orientation, phase variation, and strain vector in ultrathin TMDs. Here, it is demonstrated that SHG response of ultrathin TMDs is highly sensitive to temperature modulation. Furthermore, temperature dependent SHG is found to show opposite trends for single layer and few odd layers (3L, 5L, 7L, etc.) of TMDs. A remarkable temperature dependent SHG enhancement (25.8%) is found in single layer molybdenum diselenide (MoSe 2 ) using 900 nm laser excitation whereas few odd layers show significant temperature dependent SHG quenching which is found to be ‐55.2%, ‐31.02%, and ‐18.4% in case of 3L, 5L, and 7L of MoSe 2 . Temperature dependent SHG investigation with other TMDs, like MoS 2 , WS 2 , and WSe 2 , shows the similar trend which reveals an important structural characteristic for TMDs. Second order nonlinear susceptibility calculations considering weak van der Waal forces during thermal expansion in ultrathin TMDs show good agreement with the experimental findings. The results show SHG as a powerful and sensitive approach to investigate thermal variation in ultrathin TMDs.