1T′ Transition Metal Telluride Atomic Layers for Plasmon-Free SERS at Femtomolar Levels

• DOI: 10.1021/jacs.8b02972
• Publication Date: 2018-06-21T13:05:25Z
• Authors: Li Tao; Kun Chen; Zefeng Chen; Chunxiao Cong; Caiyu Qiu; Jiajie Chen; Ximiao Wang; Huanjun Chen; Ting Yu; Weiguang Xie; Shaozhi Deng; Jian-Bin Xu
• Keywords: Telluride; Cadmium telluride photovoltaics

Plasmon-free surface enhanced Raman scattering (SERS) based on the chemical mechanism (CM) is drawing great attention due to its capability for controllable molecular detection. However, in comparison conventional noble-metal-based SERS technique driven by plasmonic electromagnetic (EM), low sensitivity CM-based dominant barrier toward practical applications. Herein, we demonstrate 1T′ transition metal telluride atomic layers (WTe2 and MoTe2) as ultrasensitive platforms SERS. The sensitivities of analyte dyes 1T′-W(Mo)Te2 reach EM-comparable ones become even greater when it integrated with a Bragg reflector. In addition, dye fluorescence signals are efficiently quenched, making spectra more distinguishable. As proof concept, Rhodamine 6G (R6G) detectable an ultralow concentration 40 (400) fM pristine 1T′-W(Mo)Te2, corresponding enhancement factor (EF) reaches 1.8 × 109 (1.6 108). limit detection EF R6G can be further into 4 (40) 4.4 1010 (6.2 109), respectively, strong interaction between abundant density states near Fermi level semimetal combination gives rise promising effects promoting charge transfer resonance analyte-telluride complex.