Synthesis of 2D Materials via Laser Annealing on Insulating Substrates: A non-transfer, fast and patternable approach
Shao-Hsin Lee1*, Henry Medina1, Yu-Ze Chen1, Chih-Chi Huang1, Yu-Lun Chueh1
1Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:ShaoHsin Lee,
Layered materials such as graphite and transition metal dichalcogenides, have received lots of attention due to their capability to reach atomic thickness. At few atomic layers, these so called two-dimensional materials reveal outstanding physical properties. Ultra high electron mobility, high thermal conductivity for graphene and direct bandgap with superb field effect behavior in TMD’s at reduced dimensionality are some of the assets that open up a wide range of potential applications in optoelectronics, energy harvesting, Li-ion batteries and supercapacitors. However, the synthesis approach by CVD does not easily allow pattern and requires the use of high temperature processes restricting the use of substrates that can sustain such temperatures. For that reason, the films have to be transferred to additional substrates in order to exploid their potential. Therefore, further improvement of the synthesis methods is an important step to pursue. Here, we use a laser approach to induce simultaneously grow and pattern of graphene, WS2 and MoS2 directly on insulating substrates without the necessity of an additional transfer process. TEM supported by Raman and X-ray Photoelectron Spectroscopies confirm the existence and quality of the synthesized films. Field effect transistors fabricated on the synthesized graphene and photodetectors the case of WS2 show the potential for the development of practical applications. Furthermore, this approach can be extended to the synthesis of other materials. The laser annealing assisted method develops a new approach that is fast, cheap, patternable and does not require transfer giving a step forward on the technology development for practical applications.

Keywords: 2D Materials, graphene, WS2, MoS2, Laser Annealing