Tunneling study on electronic band structure of PEO/TaS2 layered nanocomposites

摘要

Electronic band structures near the Fermi level of PEO/TaS2 layered nanocomposites have been studied by tunneling spectroscopy. PEO/TaS2 layered nanocomposites were synthesized by using the exfoliation-adsorption technique. Single crystals of 1T-, 2H-, and 4Hb-TaS2 were used as host materials. The tunneling spectra of 1T- and 4Hb-TaS2 single crystals show clear charge density wave (CDW) structures. The CDW gaps disappear in the tunneling spectra of PEO/IT- and PEO/4Hb-TaS2 nanocomposites. It is found that the electronic band structures of PEO/1T-TaS2 and PEO/4Hb-TaS2 nanocomposites are metallic, while that of PEO/2H-TaS2 nanocomposites is semiconductor-like with large band gap. (c) 2006 Elsevier Ltd. All rights reserved.