English

Second harmonic study of thermally oxidized mono- and few-layer 2H-MoS2

Materials Science 2026-03-10 v1

Abstract

A comprehensive study of second harmonic generation on thermally oxidized MoS2 flakes with thickness ranging from monolayer up to seven layers is presented. Observing the fundamental nonlinear behavior for non-treated and oxidized MoS2 reveals that oxidation causes significant changes in the second harmonic (SH) response for all investigated structures. Excitation power dependent measurements to analyze the nonlinear behavior with respect to the oxidation time show progressive oxidation within the maximum oxidation time of six hours, under the considered oxidation conditions. Here, polarization dependent measurements reveal the structural changes due to oxidation. Additionally, it is found that the oxidation depth is restricted to the top most layer and the oxidation behavior exhibits a layer dependency. These findings are supported by theoretical band structure calculations. The results demonstrate that the thermal oxidation progress of two dimensional MoS2 can be monitored with non-resonant and non-invasive SH microscopy, by following distinct fingerprints of structural modification in the nonlinear response.

Keywords

Cite

@article{arxiv.2603.08461,
  title  = {Second harmonic study of thermally oxidized mono- and few-layer 2H-MoS2},
  author = {Katharina Burgholzer and Henry Volker Hübschmann and Gerhard Berth and Adriana Bocchini and Uwe Gerstmann and Wolf Gero Schmidt and Klaus D. Jöns and Alberta Bonanni},
  journal= {arXiv preprint arXiv:2603.08461},
  year   = {2026}
}

Comments

Katharina Burgholzer and Henry Volker H\"ubschmann contributed equally