Effects of Wet Transfer on Photoluminescence of WS2

ORAL

Abstract

Chemical vapor deposition (CVD)-grown transition metal dichalcogenides (TMDs) are often required to be transferred onto another substrate for device applications. The KOH-based wet transfer is the most popular method to transfer TMDs. However, after transfer, PL intensity is heavily quenched due to a combination of trappd water, substrate dope and solvent effects which are introduced during transfer process.
Here, we evaluated the effects of solvents and polymers involved in the wet etching transfer on the PL property of WS2. We used CVD-grown WS2 sample and simulate the transfer process by applying each solvent and polymer to WS2 respectively. The PL mapping results showed there is no significant reduction of PL intensity of WS2 before and after acetone, IPA, DI water and PMMA treatment. We then studied the effect of KOH on the PL intensities by transferring WS2 onto PDMS substrate using the Cu-based transfer method [1]. After 30% KOH solution treatment, the sample showed significant reduction of PL intensity compared to it before KOH treatment. We attribute that KOH molecules are physically adsorbed onto WS2, which can be removed through acid neutralization or high vacuum annealing.
[1] Z. Lin, et. al., Scientific reports, 5, 18596 (2015).

Presenters

  • Siwei Chen

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology

Authors

  • Xiaotian Wang

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology

  • Kyungnam Kang

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology

  • Shichen Fu

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology

  • Kyle Godin

    Stevens Institute of Technology

  • Siwei Chen

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology

  • Eui-Hyeok Yang

    Stevens Institute of Technology, Mechanical Engineering, Stevens Institute of Technology