Observation of Trionic Optical Gain in Electrically Gated Two-Dimensional Molybdenum Ditelluride

We report a new mechanism of optical gain originating from trions at extremely low-density levels in 2D material system by conducting systematic PL and reflectance spectroscopy on electrically-gated MoTe2 mono- and bi-layer devices. © 2019 The Author(s)