Cu2ZnSnS4 (CZTS) is an attractive material for sustainable photovoltaics and thermoelectrics, and several properties originate from its marked polymorphism. High-energy mechanical alloying is found to lead to a disordered phase that possesses a sphalerite-like cubic structure. This is investigated in detail with the aid of laboratory and synchrotron radiation X-ray diffraction, Raman spectroscopy, electron microscopy and ab initio molecular dynamics. The disordered cubic polymorph is preserved below 663 K. With thermal treatments above 663 K, the tetragonal kesterite phase forms, used here as a reference for structural and microstructural features. Particular attention is paid to the stacking arrangement: a significant fraction of twin faults was found in the disordered cubic samples, which then progressively annealed with domain growth and with the transition to the ordered tetragonal phase. This study also focuses on Debye–Waller coefficients, which were found to be considerably larger for the disordered cubic than the tetragonal sample. Indeed, disorder leads to an ∼1 Å2 upward shift through the temperature range 100–700 K, a feature confirmed by ab initio calculations, which points to a particularly high contribution from disordered Sn cations. This supports the general understanding that structural disorder introduces a temperature-independent static contribution to the atomic mean-square displacement. Debye–Waller coefficients are found to be a good measure of this disorder, known to have a critical effect on transport properties.

Static and dynamic components of Debye–Waller coefficients in the novel cubic polymorph of low-temperature disordered Cu2ZnSnS4 / Isotta, Eleonora; Mukherjee, Binayak; Bette, Sebastian; Dinnebier, Robert; Scardi, Paolo. - In: IUCRJ. - ISSN 2052-2525. - 9:2(2022), pp. 272-285. [10.1107/S2052252522000239]

Static and dynamic components of Debye–Waller coefficients in the novel cubic polymorph of low-temperature disordered Cu2ZnSnS4

Isotta, Eleonora;Mukherjee, Binayak;Scardi, Paolo
2022

Abstract

Cu2ZnSnS4 (CZTS) is an attractive material for sustainable photovoltaics and thermoelectrics, and several properties originate from its marked polymorphism. High-energy mechanical alloying is found to lead to a disordered phase that possesses a sphalerite-like cubic structure. This is investigated in detail with the aid of laboratory and synchrotron radiation X-ray diffraction, Raman spectroscopy, electron microscopy and ab initio molecular dynamics. The disordered cubic polymorph is preserved below 663 K. With thermal treatments above 663 K, the tetragonal kesterite phase forms, used here as a reference for structural and microstructural features. Particular attention is paid to the stacking arrangement: a significant fraction of twin faults was found in the disordered cubic samples, which then progressively annealed with domain growth and with the transition to the ordered tetragonal phase. This study also focuses on Debye–Waller coefficients, which were found to be considerably larger for the disordered cubic than the tetragonal sample. Indeed, disorder leads to an ∼1 Å2 upward shift through the temperature range 100–700 K, a feature confirmed by ab initio calculations, which points to a particularly high contribution from disordered Sn cations. This supports the general understanding that structural disorder introduces a temperature-independent static contribution to the atomic mean-square displacement. Debye–Waller coefficients are found to be a good measure of this disorder, known to have a critical effect on transport properties.
2
Isotta, Eleonora; Mukherjee, Binayak; Bette, Sebastian; Dinnebier, Robert; Scardi, Paolo
Static and dynamic components of Debye–Waller coefficients in the novel cubic polymorph of low-temperature disordered Cu2ZnSnS4 / Isotta, Eleonora; Mukherjee, Binayak; Bette, Sebastian; Dinnebier, Robert; Scardi, Paolo. - In: IUCRJ. - ISSN 2052-2525. - 9:2(2022), pp. 272-285. [10.1107/S2052252522000239]
File in questo prodotto:
File Dimensione Formato  
Isotta_etal_IUCrJ_9(2022)272-285.pdf

accesso aperto

Descrizione: Articolo completo
Tipologia: Versione editoriale (Publisher’s layout)
Licenza: Creative commons
Dimensione 1.97 MB
Formato Adobe PDF
1.97 MB Adobe PDF Visualizza/Apri
Isotta_etal_IUCrJ_9(2022)272-285SuppInfo.pdf

accesso aperto

Descrizione: Materiale supplementare
Tipologia: Altro materiale allegato (Other attachments)
Licenza: Creative commons
Dimensione 3.26 MB
Formato Adobe PDF
3.26 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11572/332456
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact