US EPA

4836470 

Journal Article 

Thermal conductivity determination of suspended mono- and bilayer WS2 by Raman spectroscopy 

Peimyoo, N; Shang, J; Yang, W; Wang, Y; Cong, C; Yu, T 

2015 

1 

Nano Research
ISSN: 1998-0124 

8 

4 

1210-1221 

10.1007/s12274-014-0602-0 

WOS:000353807500015 

We report the thermal conductivities of monolayer (1L) and bilayer (2L) WS2 grown by chemical vapor deposition (CVD), which are determined by use of temperature and excitation dependences of E (2g) (1) and A(1g) Raman modes. The first-order temperature coefficients of E (2g) (1) and A(1g) modes in both supported and suspended WS2 layers were extracted. The frequency shift of the A(1g) mode with temperature is larger than that of the E (2g) (1) mode for 1L-WS2, which is attributed to stronger electron-phonon coupling for the A(1g) mode than that for the E (2g) (1) mode. Moreover, by use of the shift of the phonon mode induced by laser heating, the thermal conductivities at room temperature were estimated to be 32 and 53 W/(m center dot K) for 1L- and 2L-WS2, respectively. Our results provide fundamental information about the thermal properties of WS2 layers, which is crucial for developing applications of atomically-thin WS2 devices. 

thermal conductivity; tungsten disulfide; Raman; temperature dependence; excitation power