Observation of gate-tunable excitonic emissions in suspended MoS₂

We report on observations of photoluminescence spectra from suspended MoS₂ as a function of incident excitation power and gate-tunable electron density. Recent work [1-3] demonstrated substantial red-shifting and broadening of the neutral exciton photoluminescence peak at power densities above 19 kW/cm², indicating the formation of electron-hole liquid at room temperature. However, emission characteristics in 2D systems tend to be complex, involving internal processes, such as exciton-phonon coupling [4], as well as external factors. One parameter that determines the excitonic emission characteristic is the inhomogeneous electron doping incurred in the materials during the synthesis and fabrication processes. In this work, we will examine electron-density-dependent effects on the emission and excitonic phase transitions through electrostatic doping.



[1] Y. Yu et al., ACS Nano 2023, 17 (16), 15474–15481.

[2] Y. Yu et al., ACS Nano 2019, 13 (9), 10351–10358.

[3] A. Rustagi et al., Nano Lett. 2018, 18 (1), 455–459.

[4] E. R. Adler, et al., Nanomaterials 14, 37 (2023).