Temperature- and power-dependent phonon properties of suspended few layers of tungsten diselenide

Abstract In this study we report the temperature- and power-dependence of the out-of-plane A 1 g Raman mode of mechanically exfoliated few-layered WSe 2 suspended on Si 3 N 4 holes. The A 1 g phonon frequency is red-shifted for a temperature in the range 77-548 K, with first-order temperature coefficients estimated to be -0.0083 and -0.0079 cm − 1 /K for suspended four- and six-layer WSe 2 , respectively. The power-dependence of suspended four-layer WSe 2 sample is estimated to be -0.0079 cm − 1 / μ W and no shift is observed for six-layer WSe 2 . By using the power-dependence of the suspended four layers WSe 2 and the 1D Balandin's approach, we calculate the in-plane thermal conductivity of WSe 2 at room temperature to be ∼ 57.7 W/m.K.