Valakh, M.Y.; Litvinchuk, A.P.; Dzhagan, V.M.; Yukhymchuk, V.O.; Havryliuk, Y.O.; Guc, M.; Bodnar, I.V.; Izquierdo-Roca, V.; Perez-Rodriguez, A.; Zahn, D.R.T. "Optical properties of quaternary kesterite-type Cu2Zn(Sn1-:XGex)S4 crystalline alloys: Raman scattering, photoluminescence and first-principle calculations" RSC Advances 6, 72, pp. 67756 - 67763. 2016 DOI: 10.1039/c6ra13608g