Work

Microstructural and emission properties induced by Na incorporation in pure sulphide CIGS absorber

Year: 2025

Type: article

Abstract: Pure sulphide chalcopyrite Cu(In,Ga)S 2 , referred to as CIGSu, is a promising material for the use as top cell in tandem photovoltaic applications. This report aims at investigating the influence of Na incorporation on the optical and structural properties of the CIGSu. Na treatments are indeed known to largely improve the performances of the selenide chalcopyrite Cu(In,Ga)Se 2 , leading to record efficiencies amongst the thin film technology. In this work, CIGSu layers subjected to different Na incorporation strategies were grown on Mo or ITO rear contact. The crystalline quality of the CIGSu layers was investigated by XRD diffraction showing a homogeneous phase of CIGSu. On the other hand, optical properties of CIGSu were carried out by cathodoluminescence spectroscopy. The analyses demonstrate the passivation of the CIGSu layer induced by Na incorporation. Also, the formation of an in-depth band grading inside the CIGSu layer was evidenced and linked to the Na incorporation. Moreover, atom probe tomography revealed a planar segregation of Na along the grain boundary, evidencing the diffusion of Na through the ITO rear contact.

Source: Journal of Alloys and Compounds

DOI: 10.1016/j.jallcom.2025.182582