Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 13, Issue 6, Pages 7188-7199Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.0c20539
Keywords
ACIGS; CIGS; solubility limit; atom probe; density functional theory; first-principles calculations
Funding
- Swedish Foundation for Strategic Research [RMA15-0030]
Ask authors/readers for more resources
Through experimental and theoretical studies, it has been found that there is a clear trend of increased alkali bulk solubility with the silver concentration in Cu(In,Ga)Se-2 absorbers, which can enhance the performance of photovoltaic devices.
Silver alloying of Cu(In,Ga)Se-2 absorbers for thin film photovoltaics offers improvements in open-circuit voltage, especially when combined with optimal alkali-treatments and certain Ga concentrations. The relationship between alkali distribution in the absorber and Ag alloying is investigated here, combining experimental and theoretical studies. Atom probe tomography analysis is implemented to quantify the local composition in grain interiors and at grain boundaries. The Na concentration in the bulk increases up to similar to 60 ppm for [Ag]/([Ag] + [Cu]) = 0.2 compared to similar to 20 ppm for films without Ag and up to similar to 200 ppm for [Ag]/([Ag] + [Cu]) = 1.0. First-principles calculations were employed to evaluate the formation energies of alkali-on-group-I defects (where group-I refers to Ag and Cu) in (Ag,Cu)(In,Ga)Se-2 as a function of the Ag and Ga contents. The computational results demonstrate strong agreement with the nanoscale analysis results, revealing a clear trend of increased alkali bulk solubility with the Ag concentration. The present study, therefore, provides a more nuanced understanding of the role of Ag in the enhanced performance of the respective photovoltaic devices.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available