In this work we present a theoretical calculation of the photon emission spectrum via direct and phonon-assisted intra-conduction-band transitions, assessing the impact of the approximations usually made in theoretical analysis of the phenomenon. We have compared our results to a previous work, finding a marked disagreement. Our phonon-assisted emission spectrum has a much lower effective temperature, so that it overwhelms the contribution of direct processes over the range of photon energies spanning from infrared to near-UV. We discuss qualitative arguments supporting our results presenting also a simplified model suitable for a much more efficient implementation of the spectrum calculation.

• Received 31 May 1995

DOI:https://doi.org/10.1103/PhysRevB.52.10993