Low Band Gap and Ionic Bonding with Charge Transfer Threshold in the Polymeric Lithium Fulleride Li4C60

详细信息    查看全文

• 作者：Roberto Macovez ; Rebecca Savage ; Luc Venema ; Joachim Schiessling ; Katalin Kamará ; s ; Petra Rudolf
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：February 28, 2008
• 年：2008
• 卷：112
• 期：8
• 页码：2988 - 2996
• 全文大小：183K
• 年卷期：v.112,no.8(February 28, 2008)
• ISSN：1932-7455

文摘

We demonstrate the growth of crystalline Li₄C₆₀ films. The low-energy electron diffraction pattern of thefilms indicates the formation of polymer chains in the plane of the surface, consistent with the reportedcrystal structure. Electron energy loss and photoemission spectra identify the Li₄C₆₀ polymer as a low bandgap semiconductor, with a relatively strong coupling of electrons to low-frequency stretching modes of thepolymer bonds and alkali phonons. No evidence is found for hybridization between the Li- and fullerene-derived electronic states. Instead, a partial charge transfer takes place, which is the same for different Liconcentrations. This result rationalizes the stability of the polymer phase over a wide range of stoichiometries.