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 ΔE_V is calculated to be 0.65 eV and the conduction band offset ΔE_C is 0.31 eV. The interfacial band alignment is sketched to display type-I band alignment.