Fig. 2: Determination of the indirect bandgap.

a Differential ARPES map of PdSe₂ along the \({\Gamma }^{{\prime} }\)-S\({}^{{\prime} }\) direction at a pump-probe delay of 1 ps, showing conduction band (CB) population. Dark brown indicates enhancement, while dark turquoise represents depletion. The CBM and VBM are observed simultaneously, and the black dashed lines serve as guides to the eye for the band dispersions. Vertical red and blue dashed lines mark the energy cuts at the VB and CB, respectively. b DFT calculations for the highest VB and lowest CB along the Γ-S axis at k_z = 0 (brown bands) and along \({\Gamma }^{{\prime} }\)-S\({}^{{\prime} }\) at k_z = 0.165 plane (green bands) across the BZ (for details see the text). This figure demonstrates the strong k_z dependence as the band gap changes from 0.45 eV up to 0.66 eV for k_z = 0 and k_z = 0.165, respectively. The grey shaded region indicates the energy range of defect-induced states obtained from DFT calculations (see Supplementary Information). c EDCs of the VB (red) and CB (blue), extracted along the corresponding dashed lines in (a) with an integration width of 0.04 Å⁻¹ from the absolute intensity of the TR-ARPES signal. The EDC intensity corresponding to the CB has been multiplied by a factor of 15. The bandgap at this k_z point is approximately 0.80 eV (from the VB peak to the CB peak), whereas the indirect band gap of PdSe₂ is calculated to be 0.55 eV; for details, see the main text.