Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 56: 2D Materials: Growth

HL 56.4: Vortrag

Mittwoch, 9. März 2016, 11:15–11:30, S053

TFT Fabrication Based on Liquid Exfoliated MoS₂ Flakes — •Xiaoling Zeng¹, Sonia Metel^{2, 3}, Valeria Nicolosi^{2, 3, 4}, and Veit Wagner¹ — ¹Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany — ²School of Chemistry, Trinity College Dublin, Ireland — ³CRANN, Trinity College Dublin, Ireland — ⁴School of Physics, Trinity College Dublin, Ireland

There is a large interest in establishing cheap, scalable processes for producing low dimensional semiconducting dichalcogenide films for electronic application. In this work, well exfoliated MoS₂ dispersions were prepared through two step liquid phase exfoliation process with N-methyl-pyrrolidone (NMP) and Isopropanol (IPA). The obtained exfoliated MoS₂ flakes were characterized by microscopy (TEM and SEM), Uv - Vis and Raman spectroscopy.

Bottom gate thin film transistors (TFTs) based on exfoliated MoS₂ film were fabricated by using spray coating techniques. The deposition process was optimized to get uniform and percolated MoS₂ film with different thicknesses. Transistors show only minor conductivity directly after layer deposition. However, depositing additional PMMA layer on top shows large improvement in electrical characteristics, i.e. switching behavior with changing gate voltage. Interpretation is that the PMMA layer brings the initially separated flakes into contact and enables proper percolation. Further investigation found that the thickness of PMMA influences the electrical properties. This low-cost and scalable solution-based fabrication process will promote the application of dichalcogenides in future nanoelectronic devices.