Despite the ad-hoc nature of the charge distribution functions the emission calculated by this approach 2 is comparable to the results calculated by much more sophisticated simulations that employ density functional theory to determine the electron distributions. The simulated I/I 425 spectra for interband recombination at both critical points are presented in Figure . For all λ ex , the simulated I/I 425 spectra are characterized by values significantly higher than one on the short wavelength side, followed by a steep decline for wavelengths longer than approximately 600 nm. The general shape of the spectrum reflects the shift of the interband emission to higher wavelengths for larger λ ex . The drop above 600 nm results from the reduction of the JDOS, which increasingly dominates the emission for longer wavelengths. On the short-wavelength side, the growing values for I/I 425 with increasing λ ex correspond to an increasing PL. The growing I/I 425 maximum can be understood by noting that the fraction of the PL spectrum that falls within the spectral window of the measurement increases as λ ex approaches the cutoff wavelength of the filter (> 550 nm).