The resulting I/I 425 -spectrum is a measure of the change in the recombination integral that directly reflects the emission mechanism. Figure presents I/I 425 for all λ ex measured in window I. The spectrum is characterized by a smooth slope. Its amplitude remains generally below one and decreases further with increasing λ ex , with the decline being more pronounced in the short-wavelength range than on the long-wavelength side. To identify the nature of the emission process, we compared these spectra to simulated I/I 425 -spectra expected for inter-and intraband recombination using Equation . hole populations. An exponential form is assumed for the excited populations to account for the relaxation processes before recombination. In our simulation, we used a rough estimate for the exponential width of about 80 meV, obtained from the lifetime of d -band holes of τ h < 50 fs. An example of f e (E i , T ) (electrons, blue) and f h (E f , T ) (holes, red) after excitation at λ ex =420 nm is depicted in Figure . Details on the distribution can be found in the SI.