Band Bending at Semiconductor Interfaces and Its Effect on Photoemission Line-Shapes

We show that, contrary to intuition and under normal experimental conditions, the band bending at a semiconductor surface or interface does not strongly increase the linewidth of photoemission core-level peaks. The increase is smaller than the magnitude of the band bending, and in most cases negligible. Non-negligible increases are found only when the linewidth is smaller than and, simultaneously, the photoelectron escape depth larger than in a typical experiment.