Research Article


2014, 7(7): 973–980


Enhanced photocurrent and photoluminescence spectra in MoS2 under ionic liquid gating

Zhen Li1, Shun-Wen Chang2, Chun-Chung Chen1, and Stephen B. Cronin1,2 (*

View Author's information

1 Department of Electrical Engineering, 

2 Department of Physics, University of Southern California, 3737 Watt Way, PHE 624 Los Angeles, CA 90089, USA

Keywords: ionic liquid, dichalcogenide, MoS2, photoluminescence, photocurrent, passivation
Full article PDF
Cite this article(Endnote)
Share this article

views: 136

Citations: 0

  • Abstract
  • References
  • Electronic Supplementary Material
We report substantial improvements and modulation in the photocurrent (PC) and photoluminescence (PL) spectra of monolayer MoS2 recorded under electrostatic and ionic liquid gating conditions. The photocurrent and photoluminescence spectra show good agreement with a dominant peak at 1.85 eV. The magnitude of the photoluminescence can be increased 300% by ionic liquid gating due to the passivation of surface states and trapped charges that act as recombination centers. The photocurrent also doubles when passivated by the ionic liquid. Interestingly, a significant shift of the PL peak position is observed under electrostatic (14 meV) and ionic liquid (30 meV) gating, as a result of passivation. The ionic liquid provides significant screening without any externally applied voltage, indicating that these surface recombination centers have net charge. The acute sensitivity of monolayer MoS2 to ionic liquid gating and passivation arises because of its high surface-to-volume ratio, which makes it especially sensitive to trapped charge and surface states. These results reveal that, in order for efficient optoelectronic devices to be made from monolayer MoS2, some passivation strategy must be employed to mitigate the issues associated with surface recombination.
Related Article
Cite this article

Enhanced photocurrent and photoluminescence spectra in MoS2 under ionic liquid gating. Nano Res. 2014, 7(7): 973–980

Download citation