Fig. 1: Excitons in MoS₂ bilayer and white light absorption.

a Schematic of the band structure (around the K point) of the bilayer MoS₂ showing (black arrows) the participation of the different bands in the IE formation. The blue and red colors represent the up and down spin, respectively. L₁ and L₂ refer to the layer 1 and layer 2 of the bilayer MoS₂, respectively. b Schematic showing the two possible charge configurations in the absence of bias voltage between the two layers. In both cases, the electron is localized in one of the layers, and the hole is distributed among both the layers. c White-light differential reflection at 7 K showing three dips corresponding to A, IE, and B exciton, respectively. d Relative shift of excitonic features observed in instantaneously-probed pulsed reflectivity with increasing exciton density. Pulse duration = 20 ps. The K valley lifetime of A exciton (45 fs) and IE (53 fs) estimated from their respective linewidths are used to estimate the exciton density from the pump fluence. The error bars represent the variance of the fitted parameters caused by noise in the measurement.