Atmospheric-pressure CVD growth of two-dimensional 2H- and 1 T'-MoTe2films with high-performance SERS activity

Bikram Adhikari; Tej B Limbu; Kizhanipuram Vinodgopal; Fei Yan

doi:10.1088/1361-6528/abff8f

Atmospheric-pressure CVD growth of two-dimensional 2H- and 1 T'-MoTe₂films with high-performance SERS activity

Nanotechnology. 2021 May 24;32(33). doi: 10.1088/1361-6528/abff8f.

Authors

Bikram Adhikari¹, Tej B Limbu¹, Kizhanipuram Vinodgopal¹, Fei Yan¹

Affiliation

¹ Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, United States of America.

PMID: 33971633
DOI: 10.1088/1361-6528/abff8f

Abstract

Two-dimensional (2D) molybdenum ditelluride (MoTe₂) is a member of the transition-metal dichalcogenides family, which is an especially promising platform for surface-enhanced Raman scattering (SERS) applications, due to its excellent electronic properties. However, the synthesis of large-area highly crystalline 2D MoTe₂with controllable polymorphism is a huge challenge due to the small free energy difference (∼40 meV per unit cell) between semiconducting 2H-MoTe₂and semi-metallic 1 T'-MoTe₂. Herein, we report an optimized route for the synthesis of 2H- and 1 T'-MoTe₂films by atmospheric-pressure chemical vapor deposition. The SERS study of the as-grown MoTe₂films was carried out using methylene blue (MB) as a probe molecule. The Raman enhancement factor on 1 T'-MoTe₂was found to be three times higher than that on 2H-MoTe₂and the 1 T'-MoTe₂film is an efficient Raman-enhancing substrate that can be used to detect MB at nanomolar concentrations. Our study also imparts knowledge on the significance of a suitable combination of laser excitation wavelength and molecule-material platform for achieving ultrasensitive SERS-based chemical detection.

Keywords: SERS; chemical vapor deposition; phase change material; transition-metal dichalcogenides.