Gemini 06 Ball Sunan Wangwan
Gemini 06 Ball Sunan Wangwan 2
Molybdenum disulfide (MoS 2) is systematically studied using Raman spectroscopy with ultraviolet and visible laser lines. It is shown that only the Raman frequencies of and peaks vary monotonously with the layer number of ultrathin MoS 2 flakes, while intensities or widths of the peaks vary arbitrarily. The coupling between electronic transitions and phonons are found to become weaker when the layer number of MoS 2 decreases, attributed to the increased electronic transition energies or elongated intralayer atomic bonds in ultrathin MoS 2. The asymmetric Raman peak at 454 cm −1, which has been regarded as the overtone of longitudinal optical M phonons in bulk MoS 2, is actually a combinational band involving a longitudinal acoustic mode (LA(M)) and an optical mode ( ). Our findings suggest a clear evolution of the coupling between electronic transition and phonon when MoS 2 is scaled down from three‐ to two‐dimensional geometry. Does gold bond dark spot minimizing work.