Wide-Gap Cu(In,Ga)Se2Solar Cells with Zn(O,S) Buffer Layers Prepared by Atomic Layer Deposition

• DOI: 10.7567/jjap.51.10nc15
• Publication Date: 2013-12-21T15:21:24Z
• Authors: Kazuya Nakashima; Toyokazu Kumazawa; Taizo Kobayashi; Takahiro Mise; Tokio Nakada
• Keywords: Open-circuit voltage; Buffer (optical fiber); Deposition; Band offset

Wide-gap Cu(In0.4,Ga0.6)Se2 solar cells with Zn(O,S) buffer layers deposited by atomic layer deposition (ALD) technique have been investigated. The band-gap energy (Eg) of the estimated optical transmission and reflection measurements was varied from 3.2 to 3.6 eV. sulfur (S)-poor showed a low open-circuit voltage (VOC) owing cliff nature conduction band offset (CBO). In contrast, S-rich short-circuit current density (JSC) spike CBO. Even if CBO values were adequate, best cell efficiencies considerably low. These results suggest that main cause for is not interface recombination at Zn(O,S)/Cu(In,Ga)Se2 interface, but mainly bulk in Cu(In,Ga)Se2 (CIGS) absorber layer.