Optical Spectra and Electronic Band Structure Calculations of β‘ ‘-(ET)2SF5RSO3 (R = CH2CF2, CHFCF2, and CHF):  Changing Electronic Properties by Chemical Tuning of the Counterion

• Published in: Chemistry of materials Vol. 12; no. 8; pp. 2490 - 2495
• Main Authors: Jones, B. R, Olejniczak, I, Dong, J, Pigos, J. M, Zhu, Z. T, Garlach, A. D, Musfeldt, J. L, Koo, H.-J, Whangbo, M.-H, Schlueter, J. A, Ward, B. H, Morales, E, Kini, A. M, Winter, R. W, Mohtasham, J, Gard, G. L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 21.08.2000
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron density of states and band structure of crystalline solids; Electron states; Exact sciences and technology; Infrared and raman spectra and scattering; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Organic compounds, polymers; Physics; Polymers and organic compounds; Band structure; Reflection spectrum; Tight binding approximation; Organic conductors; Vibrational modes; Infrared spectra; Experimental study; Extended Hueckel method; Optical conductivity
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm000349l

We report the polarized infrared reflectance spectra, optical conductivity, and electronic band structure of metallic β‘ ‘-(ET)2SF5CHFSO3 and compare our results with those of the β‘ ‘-(ET)2SF5CH2CF2SO3 superconductor and the β‘ ‘-(ET)2SF5CHFCF2SO3 metal/insulator material. We discuss the electronic structure of these organic molecular solids in terms of band structure, many-body effects, and disorder. On the basis of spectral similarities between the superconductor and metallic salts and structural differences in the anion pocket of all three, we conclude that the unusual electronic excitations observed in the β‘ ‘-(ET)2SF5CHFCF2SO3 metal/insulator material are not caused by electron correlation but are due to disorder-related localization.