GaAs/InP and InAs/InP heterojunction band offsets measured by x‐ray photoemission spectroscopy

X‐ray photoemission spectroscopy (XPS) has been used to measure the unstrained valence‐band offset ΔEv for the x=0 and x=1 end points of the Inx Ga1−x As/InP (100) heterojunction system. Although the GaAs/InP (100) and InAs/InP (100) pseudomorphic interfaces investigated are strained because of lattice mismatch, the ΔEv values obtained by the XPS measurement analysis used are interpreted as characteristic of an unstrained interface. Strain‐free values of ΔEv (GaAs/InP)=0.19 eV and ΔEv (InAs/InP)=0.31 eV are reported. A linear interpolation of these x=0 and x=1 unstrained values gives ΔEv (In0.53 Ga0.47 As/InP)=0.25 eV (ΔEc/ΔEv =58/42) for the lattice‐matched interface.