Could anyone tell me what is band filling effect? I have search Physics.stackexchange and Google, but didn't find any useful information. I'll appreciate it if anyone can tell me the physical image of band filling effect.
This effect leads to a blue-shift of the luminescence, absorption, gain spectra of semiconductors with increasing of the concentration of carriers. It happens because of occupying of low-energy states of energy bands by particles. Consequently, due to the Pauli exclusion principle, transitions between occupied states in valence and conduction bands are forbidden and the possible transition, in this case, appears for higher photon energies only (higher comparing with the band gap).
Takahiro Numai, "Fundamentals of Semiconductor Lasers" (see p. 119)
see also Fig. 13 here http://online.lesn.lehigh.edu/courses/mat435/lectures/nonlin/non1.htm