Patterned Photoluminescence in Gr/MoS² heterostructure using a contact mode atomic force microscope

Chak Ming Liu^1*, W.H Chang¹, W.C Lin¹

¹物理系, 國立師範大學, 台北市, Taiwan

* Presenter:Chak Ming Liu, email:edward2010619@gmail.com

In this study, it has been proven that the AFM tip cleans PMMA and graphene ruptured by contact force. The graphene transfer on MoS² used the wet method. Gr/MoS² is rubbed by the tip of AFM in a 10*10 μm area, and the contact force is tuned from 110 to 660nN. Graphene is easily torn by a contact force exceeding 220nN, as shown in the optical image. After the transfer process, the photoluminescence intensity ratio of MoS² is reduced by about 97% and a redshift occurs. After the rubbing process, the photoluminescence intensity of MoS² tends to return to the original, because the graphene coverage breaks as the contact force increases. Optical images, PL mapping, and KPFM are used for the characterization of the graphene surface rubbed by the AFM tip. Finally, the graphene layer could be patterned by AFM tip lithography, and then 660nN cracked to expose the 4*4 μm MoS² area. As a result, cracked graphene can be used to create different structures to develop unique multilayer-2D material devices.

Keywords: Patterned, heterostructure, contact mode atomic force microscope, rubbed, Photoluminescence