title: Structural Polymorphism in "Kesterite" Cu2ZnSnS4: Raman Spectroscopy and First-Principles Calculations Analysis.
abstract: This work presents a comprehensive analysis of the structural and vibrational properties of the kesterite Cu2ZnSnS4(CZTS, I4̅ space group) as well as its polymorphs with the space groups P4̅2c and P4̅2m, from both experimental and theoretical point of views. Multiwavelength Raman scattering measurements performed on bulk CZTS polycrystalline samples were utilized to experimentally determine properties of the most intense Raman modes expected in these crystalline structures according to group theory analysis. The experimental results compare well with the vibrational frequencies that have been computed by first-principles calculations based on density functional theory. Vibrational patterns of the most intense fully symmetric modes corresponding to the P4̅2c structure were compared with the corresponding modes in the I4̅ CZTS structure. The results point to the need to look beyond the standard phases (kesterite and stannite) of CZTS while exploring and explaining the electronic and vibrational properties of these materials, as well as the possibility of using Raman spectroscopy as an effective technique for detecting the presence of different crystallographic modifications within the same material.
authors.affiliation: National Renewable Energy Laboratory (NREL) , Golden, Colorado 80401, United States.|NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899-6102, United States.|Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre , 1, 08930 Sant Adrià de Besòs, Barcelona, Barcelona, Spain.
authors.forename: Mirjana
authors.identifier: http://orcid.org/0000-0002-9439-1019
authors.initials: M
authors.lastname: Dimitrievska
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa , Via Dodecaneso 31, 16146, Genoa, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Boero
authors.affiliation: Texas Center for Superconductivity and Department of Physics, University of Houston , Houston, Texas 77204-5002, United States.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Litvinchuk
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa , Via Dodecaneso 31, 16146, Genoa, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Delsante
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa , Via Dodecaneso 31, 16146, Genoa, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Borzone
authors.affiliation: Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre , 1, 08930 Sant Adrià de Besòs, Barcelona, Barcelona, Spain.|IN2UB, Universitat de Barcelona , C. Martí Franquès 1, 08028 Barcelona, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Perez-Rodriguez
authors.affiliation: Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre , 1, 08930 Sant Adrià de Besòs, Barcelona, Barcelona, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Izquierdo-Roca