P57.00003. Comparative KPFM measurements on doped monolayer MoS2

Presented by: Christina McGahan


Tuning the electrical properties of monolayer MoS2 through doping allows better control and flexibility over future device design. Here we present electrical measurements on sulfur-rich and oxygen-rich MoS2 flakes using kelvin probe force microscopy (KPFM) and a field effect transistor sample geometry, allowing us to resolve spatial variations. Preliminary KPFM measurements show that oxygen-rich MoS2 has a larger work function than sulfur-rich MoS2 and that the work function of monolayer MoS2 differs from that of multilayer MoS2. The trend in work functions between differently doped MoS2 flakes observed via KPFM is consistent with the trend in threshold voltages extracted from bulk current-voltage measurements on the flakes as well as the trend in work functions calculated via density functional theory. The sensitivity of the shift in work function of the MoS2 flakes from an applied gate voltage suggests that local density of states measurements can be extracted with KPFM to experimentally examine the energy levels of the differently doped monolayer MoS2 flakes.


  • Christina McGahan
  • Pin-Chun Shen
  • Yuxuan Lin
  • Ashley Cavanagh
  • Tomas Palacios
  • Jing Kong
  • Katherine Aidala


Powered by Q-CTRL

© 2020 Virtual APS March Meeting. All rights reserved.