M Thripuranthaka, Late Dattatray J
Physical & Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Babha Road, Pashan, Pune 411008, India.
ACS Appl Mater Interfaces. 2014 Jan 22;6(2):1158-63. doi: 10.1021/am404847d. Epub 2014 Jan 6.
Atomically thin two-dimensional tungsten disulfide (WS2) sheets have attracted much attention due to their potential for future nanoelectronic device applications. We report first experimental investigation on temperature dependent Raman spectra of single-layer WS2 prepared using micromechanical exfoliation. Our temperature dependent Raman spectroscopy results shows that the E(1)2g and A1g modes of single-layer WS2 soften as temperature increases from 77 to 623 K. The calculated temperature coefficients of the frequencies of 2LA(M), E(1)2g, A1g, and A1g(M) + LA(M) modes of single-layer WS2 were observed to be -0.008, -0.006, -0.006, and -0.01 cm(-1) K(-1), respectively. The results were explained in terms of a double resonance process which is active in atomically thin nanosheet. This process can also be largely applicable in other emerging single-layer materials.
原子级薄的二维二硫化钨（WS2）片层因其在未来纳米电子器件应用中的潜力而备受关注。我们首次报道了对使用微机械剥离法制备的单层WS2的温度依赖拉曼光谱的实验研究。我们的温度依赖拉曼光谱结果表明，随着温度从77 K升高到623 K，单层WS2的E(1)2g和A1g模式会软化。观察到单层WS2的2LA(M)、E(1)2g、A1g和A1g(M) + LA(M)模式频率的计算温度系数分别为-0.008、-0.006、-0.006和-0.01 cm(-1) K(-1)。这些结果是根据在原子级薄纳米片中活跃的双共振过程来解释的。该过程在很大程度上也适用于其他新兴的单层材料。
