Figure 3.

O 1s core-level spectra, band bending model, and ferromagnetic polaron model. The O 1s core-level spectra for x = 0.10 are shown with a conceptual diagram for the photoinduced change of the band bending and for the ferromagnetic polaron. The O 1s photoemission spectra were taken before and under the ultraviolet illumination. The arrow indicates the spectral shift and narrowing due to the illumination. The profiles of the O 1s core level, valence-band maximum, and conduction-band minimum are shown in the conceptual diagram.