“…ratio between emitted photons and injected electrons (e) [19,20], depends on the optical emission of the material [30][31][32][33][34][35][36][37], as well as on its doping level [6,[38][39][40][41]. In doped 1L-TMDs, the PL and EL emission originates from either negative (X − ) [28,33,34,38] or positive (X + ) [6,19,20] trions, depending on the type of doping. However, 1L-TMD-LEDs based on trionic emission show low η EL (typically <0.05% [19,20]) with respect to neutral exciton (X 0 ) emission (typically η EL <1% [6,7,31,32,38,39]).…”