Fig. 4: Correlated states of CLL trions, inter-layer excitons and their mixtures.

a–d Electric field-dependent photoluminescence (PL) emission at the excitation power of ~ 1.2 μW (a), 8.8 μW (b), 62 μW (c), and 271 μW (d) from Device 2. White arrows indicate the locations of PL intensity jumps in the charge-layer-locked trion (CLL trion) band and inter-layer exciton (IX) band. e–h Corresponding PL integrated intensity ratios of CLL trions (red dots) and inter-layer excitons (blue dots) as functions of the electric field under the excitation power of ~ 1.2 μW (e), 8.8 μW (f), 62 μW (g), and 271 μW (h). Shaded regions in the PL ratio plot highlight step-like features associated with CLL trions (red) and inter-layer excitons (blue). i, j Schematic illustration of the correlated states associated with the CLL trions and inter-layer excitons (correlated CLL trion-IX state) (i) and the correlated inter-layer exciton state (correlated IX state) (j).