Voids in Kesterites and the Influence of Lamellae Preparation by Focused Ion Beam for Transmission Electron Microscopy Analyses

• Autor(a) principal: Ribeiro-Andrade, Rodrigo
• Data de Publicação: 2019
• Outros Autores: Sahayaraj, Sylvester, Vermang, Bart, Correia, M. Rosario, Sadewasser, Sascha, Gonzalez, Juan Carlos, Fernandes, P. A., Salome, Pedro M. P.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/17164
• topic: Cu2 ZnSn(S, Se)4 (CZTSSe); Focused Ion Beam (FIB); Kesterite; Thin-film solar cells; Transmission electron microscopy (TEM)

Kesterite solar cells based on Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 (CZTSe) are potential future candidates to be used in thin-film solar cells. The technology still has to be developed to a great extent and for this to happen, high levels of confidence in the characterization methods are required, so that improvements can be made on solid interpretations. In this study, we show that the interpretations of one of the most used characterization techniques in kesterites, scanning transmission electron microscopy (STEM), might be affected by its specimen preparation when using focused ion beam (FIB). Using complementary measurements based on scanning electron microscopy and Raman scattering spectroscopy, compelling evidence shows that secondary phases of ZnSe mixed in the bulk of CZTSe are the likely cause of the appearance of voids in STEM lamellae. Sputtering simulations support this interpretation by showing that Zn in a ZnSe matrix is preferentially sputtered compared with any metal atom in a CZTSe matrix.