Electronic structures of organic salts (DI-DCNQI) 2M (M=Cu and Ag) using photoelectron spectromicroscopy

• Published in: Solid state communications Vol. 110; no. 1; pp. 17 - 22
• Main Authors: Haruyama, Y., Nath, K.G., Kimura, S., Ufuktepe, Y., Kinoshita, T., Hiraki, K., Kanoda, K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.1999; Elsevier
• Subjects: A. Organic crystals; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Electronic band structure; E. Photoelectron spectroscopies; E. Synchrotron radiation; Electron and ion emission by liquids and solids; impact phenomena; Electron density of states and band structure of crystalline solids; Electron states; Exact sciences and technology; Photoemission and photoelectron spectra; Physics; Polymers and organic compounds; Polymers; organic compounds; E. Photoelectron spectroscopies; E. Synchrotron radiation; D. Electronic band structure; A. Organic crystals; Ultraviolet radiation; Electronic structure; Photoionization; Organic conductors; Organic salt; Hybridization; Experimental study; Cross sections; Photoelectron spectroscopy; Synchrotron radiation
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/S0038-1098(99)00039-3

The electronic structures of organic salts (DI-DCNQI) 2M with M=Cu and Ag, where DI-DCNQI is 2,5-diiodo- N, N′-dicyanoquinonediimine, were studied using photoelectron spectromicroscopy at various photon energies. From the photon energy dependence of the photoionization cross-section, the atomic orbital characters of the observed spectral features were determined. For both (DI-DCNQI) 2Cu and (DI-DCNQI) 2Ag, the C and N 2p states originating in the cyano group and the quinone ring are located at ∼4.0 and ∼6.5 eV, respectively. The Cu 3d states for (DI-DCNQI) 2Cu and the Ag 4d states for (DI-DCNQI) 2Ag are located at ∼3.2 and ∼5.2 eV, respectively. This indicates that the pπ–d hybridization at the Fermi level between the M ions and the N atoms of the DCNQI columns is larger for (DI-DCNQI) 2Cu than for (DI-DCNQI) 2Ag. The reason for the difference in the electronic structure between (DI-DCNQI) 2Cu and (DMe-DCNQI) 2Cu is also discussed.