Growth and characterization of Cu2ZnSn(S,Se)4 thin films for solar cells

Salomé, P. M. P.; Malaquias, J.; Fernandes, P. A.; Ferreira, M. S.; Cunha, A. F. da; Leitão, J. P.; González, J. C.; Matinaga, F. M.

http://hdl.handle.net/10400.22/3429

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
ART_PSalome_2012_DFI.pdf		706.63 KB	Adobe PDF	Download

Send Feedback

Authors

Abstract(s)

Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) with their band gap energies around 1.45 eV and 1.0 eV, respectively, can be used as the absorber layer in thin film solar cells. By using a mixture of both compounds, Cu2ZnSn(S,Se)4 (CZTSSe), a band gap tuning may be possible. The latter material has already shown promising results such as solar cell efficiencies up to 10.1%. In this work, CZTSSe thin films were grown in order to study its structure and to establish the best growth precursors. SEM micrographs reveal an open columnar structure for most samples and EDS composition profiling of the cross sections show different selenium gradients. X-ray diffractograms show different shifts of the kesterite/stannite (1 1 2) peak, which indicate the presence of CZTSSe. From Raman scattering analysis, it was concluded that all samples had traces of CZTS and CZTSSe. The composition of the CZTSSe layer was estimated using X-ray diffraction and Raman scattering and both results were compared. It was concluded that Se diffused more easily in precursors with ternary Cu–Sn–S phases and metallic Zn than in precursors with ZnS and/or CZTS already formed. It was also showed that a combination of X-ray diffraction and Raman scattering can be used to estimate the ratio of S per Se in CZTSSe samples.