CMOS Inverters and P-N Junction Diodes Based on Transition Metal Dichalcogenide Monolayers
In this study, we fabricated ion-gel-gated EDLTs using large-area TMDC monolayers, MoS2, MoSe2 and WSe2, grown by chemical vapor deposition [3-6]. The Fermi level of TMDCs can be continuously shifted by applying gate voltage, and we can induce both hole and electron transport in these devices. The hole mobility of WSe2 can be enhanced up to 90 cm2/Vs at high carrier density of 1014 cm-2, whereas the MoS2 showed electron mobility of 60 cm2/Vs. By combining MoS2 and WSe2, we demonstrated complementary logic inverters, which yielded extremely high voltage gain of 110 that is the highest value in atomically thin 2D materials. We also introduce unique techniques to form stable pn junctions in ambipolar TMDC EDLTs and investigate its optoelectronic properties.
 Q. H. Wang, et al., Nat. Nanotechnol. 7, 699 (2012).
 J. T. Ye, et al., Science. 338, 1193 (2012).
 J. Pu, L.-J. Li, T. Takenobu, et al., Nano Lett. 12, 4013 (2012).
 J.-K. Huang, T. Takenobu, L.-J. Li, et al., ACS Nano. 8, 923 (2014).
 J. Pu, L.-J. Li, T. Takenobu, et al., Appl. Phys. Lett., 103, 23505 (2013).
 J. Pu, L.-J. Li and T. Takenobu, Phys. Chem. Chem. Phys., 10.1039/C3CP55270E (2014).