We used X-ray photoelectron spectroscopy (XPS) to measure the energy discon
tinuity in the valence band (Delta E-v) of Ga1-xNxAs/AlAs (x = 0, 0.014, 0.
034) and estimated Delta E-v of GaNAs/GaAs by using the Al2p energy level a
s a reference. The change in Delta E-v for GaNAs/GaAs with an increasing ni
trogen content was -(0.019 +/- 0.053) eV/%N. This suggests that the valence
-band edge (E-v) in GaNAs decreases in proportion to the nitrogen content.
Based on the decrease in the bandgap energy of GaNAs, we found that the ene
rgy discontinuity in the conduction band (Delta E-c) of GaNAs/GaAs is - (0.
175 +/- 0.053) eV/%N. This large effect of bandgap bowing on the conduction
band indicates that an ideal carrier confinement in the well can be obtain
ed by using GaInNAs as an active layer in long-wavelength laser diodes.