标题：Modification of WS2nanosheets with controllable layers via oxygen ion irradiation
作者：Song, Honglian ;Yu, Xiaofei ;Chen, Ming ;Qiao, Mei ;Wang, Tiejun ;Zhang, Jing ;Liu, Yong ;Liu, Peng ;Wang, Xuelin
作者机构：[Song, Honglian ;Yu, Xiaofei ;Chen, Ming ;Qiao, Mei ;Wang, Tiejun ;Zhang, Jing ;Liu, Yong ;Liu, Peng ;Wang, Xuelin ] School of Physics, Key Laboratory 更多
来源：Applied Surface Science
摘要：As one kind of two-dimensional materials, WS2nanosheets have drawn much attention with different kinds of research methods. Yet ion irradiation method was barely used for WS2nanosheets. In this paper, the structure, composition and optical band gap (Eg) of the multilayer WS2films deposited by chemical vapor deposition (CVD) method on sapphire substrates before and after oxygen ion irradiation with different energy and fluences were studied. Precise tailored layer-structures and a controllable optical band gap of WS2nanosheets were achieved after oxygen ion irradiation. The results shows higher energy oxygen irradiation changed the shape from triangular shaped grains to irregular rectangle shape but did not change 2H-WS2phase structure. The intensity of E2g1(Г) and A1g(Г) modes decreased and have small shifts after oxygen ion irradiation. The peak frequency difference between the E2g1(Г) and A1g(Г) modes (Δω) decreased after oxygen ion irradiation, and this result indicates the number of layers decreased after oxygen ion irradiation. The Egdecreased with the increase of the energy and the fluence of oxygen ions. The number of layers, thickness and optical band gap changed after ion irradiation with different ion fluences and energies. The results proposed a new strategy for precise control of multilayer nanosheets and demonstrated the high applicability of ion irradiation in super-capacitors, field effect transistors and other applications.
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