Impact of vapor phase Ge incorporation and reaction pathways on the performance and stability of Cu 2 Zn(Ge,Sn)Se 4 solar cells

Key Points

• The aim is to investigate how vapor phase Ge incorporation and various reactions affect the performance and stability of Cu2Zn(Ge,Sn)Se4 solar cells.
• Examined the impact of Cu/Sn precursor ratio on composition shifts
• Analyzed defects linked to SnSe2−x and GeSe2−x vapors
• Applied post-deposition treatments to enhance performance
• Achieved 12.5% solar cell efficiency at Ge/(Ge + Sn) = 9%
• Identified a promising physical route for improving solar cell performance despite similar end compositions