Investigating Raman spectra and density functional theory calculations on SrAl2O4 polymorphs

• Published in: Journal of Raman spectroscopy Vol. 50; no. 1; pp. 91 - 101
• Main Authors: Rojas‐Hernandez, Rocío Estefanía, More, Wilfredo, Rubio‐Marcos, Fernando, Fernandez, José Francisco
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01-01-2019
• Subjects: Data processing; Density functional theory; long‐lasting; molten salt; Photovoltaic cells; Polymorphism; Qualitative analysis; Raman spectra; Raman spectroscopy; Security; Solar cells; SrAl2O4
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.5497

SrAl2O4 is a long‐lasting material that combines several favorable attributes in comparison with their inorganic luminescent predecessor. In addition, it is an intriguing material combining a structural polymorphism with potential application such as in solar cells, biological labeling and imaging, and security encode. Here, we unambiguously determinate the Raman spectra for hexagonal and monoclinic polymorphs. Specifically, the Raman mode assignment of phonon modes obtained experimentally is done for the first time by modeling these structures following the principle calculations within the framework of the density functional theory. Several functionals are evaluated, considering the agreement of the calculated modes with the experimental data. The optimized structure is obtained, first, on the basis of minimizing the total energy of the structure. The calculated vibrational modes show qualitative agreement with the experimental observation. This study offers a new insight to study the relationships between structural and optical behavior in this system, providing tools to design new technological applications.
Joining experimental and theoretical work makes possible an in‐depth understanding on hexagonal and monoclinic SrAl2O4 polymorphs. The results shown are in agreement with simulations. Therefore, the coupling between the structure and the optical behavior offers a new insight in this system, providing tools to design new technological applications.