In-Situ SRPES Study on the Band Alignment of (0001)CdS/CdTe Heterojunction

The band alignment of a (0001)CdS/CdTe heterojunction is in situ studied by synchrotron radiation photoemission spectroscopy (SRPES). The heterojunction is formed through stepwise deposition of a CdTe film on a wurtzite (0001)CdS single crystalline substrate via molecular beam epitaxy. CdS shows an upward band bending of 0.55 eV, the valence band offset ΔEV is calculated to be 0.65 eV and the conduction band offset ΔEC is 0.31 eV. The interfacial band alignment is sketched to display type-I band alignment.