Resonant Raman spectroscopy study of swift heavy ion irradiated MoS2
Resonant Raman spectroscopy study of swift heavy ion irradiated MoS2
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快重离子辐照MoS2的共振拉曼光谱研究
DOI：
10.1016/j.nimb.2016.05.018
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发表时间：
2016-08-15
影响因子：
1.3
通讯作者：
Liu, Jie
中科院分区：
文献类型：
--
作者：
Guo, Hang;Sun, Youmei;Liu, Jie
二硫化钼 (MoS2) 晶体样品经快重离子（Bi-209 和 Fe-56）辐照。通过原子力显微镜在辐照的MoS2表面观察到小丘状潜迹。通过共振拉曼光谱和紫外-可见光谱 (UV-Vis) 研究了辐照 MoS2 性能的变化。辐照后在面内E-2g(1)峰（类似于383.7 cm-1）附近出现一个新峰（E-1u(2), 385.7 cm-1）。由于结构缺陷和应力随着注量的增加，两个峰值向较低频率移动并变宽。当用高能量密度照射时，另外两个新峰出现在接近190和接近230 cm(-1)处。类似于 230 cm(-1) 处的峰值是无序诱导的 LA(M) 模式。该模式的存在表明由辐射引起的缺陷。近似460 cm(-1)处的特征由2LA(M)(近似458 cm(-1))和A(2u)(近似466 cm(-1))模式组成。随着注量的增加，2LA(M) 和 A(2u) 之间的积分强度比增加。 2LA(M)模式的相对增强与LA(M)模式的出现一致，两者都证明了辐照MoS2中的结构紊乱。由于MoS2激子能量的降低，与423-cm(-1)相似的峰向较低频率移动，紫外-可见光谱结果证明了这一点。激子能量的降低可能是由于带隙中引入了缺陷能级。 (C) 2016 Elsevier B.V. 保留所有权利。
Molybdenum disulphide (MoS2) crystal samples were irradiated by swift heavy ions (Bi-209 and Fe-56). Hillock-like latent tracks were observed on the surface of irradiated MoS2 by atomic force microscopy. The modifications of properties of irradiated MoS2 were investigated by resonant Raman spectroscopy and ultraviolet-visible spectroscopy (UV-Vis). A new peak (E-1u(2), 385.7 cm(-1)) occurs near the in-plane E-2g(1) peak (similar to 383.7 cm-1) after irradiation. The two peaks shift towards lower frequency and broaden due to structural defects and stress with increasing fluence. When irradiated with high fluence, two other new peaks appear at similar to 190 and similar to 230 cm(-1). The peak at similar to 230 cm(-1) is disorder-induced LA(M) mode. The presence of this mode indicates defects induced by irradiation. The feature at similar to 460 cm(-1) is composed of 2LA(M) (similar to 458 cm(-1)) and A(2u) (similar to 466 cm(-1)) mode. With increasing fluence, the integrated intensity ratio between 2LA(M) and A(2u), increases. The relative enhancement of 2LA(M) mode is in agreement with the appearance of LA(M) mode, which both demonstrate structural disorder in irradiated MoS2. The similar to 423-cm(-1) peak shifts toward lower frequency due to the decrease in exciton energy of MoS2, and this was demonstrated by the results of UV-Vis spectra. The decrease in exciton energy could be due to introduction of defect levels into band gap. (C) 2016 Elsevier B.V. All rights reserved.