BAND ALIGNMENT AT CDS/CUINS2 HETEROJUNCTION

Band offsets at CdS/CulnS(2) heterojunctions are studied by x-ray photoemission spectroscopy. At the CdS/cyanide-treated CulnS(2) junction, the conduction band offset is as small as -0.05 +/- 0.15 eV, while the valence band offset is 1.18 +/- 0.10 eV. The CdS/Cu-rich CulnS(2) heterojunction without the treatment, however, possesses a conduction band offset of similar to -0.7 eV. This result suggests that the cyanide treatment improves the interface to give rise to the alignment of the conduction band minima, which is suitable to the solar cell applications. (C) 1995 American Institute of Physics.