## Abstract

The temperature dependence of the low-energy tail of the interband optical absorption band at the Peierls edge has been studied in halogen-bridged linear-chain complexes, [Pt(en(Formula presented)][Pt(en(Formula presented)(Formula presented)]((Formula presented)(Formula presented) and [Pt(en(Formula presented)][Pt(en(Formula presented)(Formula presented)]((Formula presented)(Formula presented), en being ethylenediamine. The absorption spectrum and its temperature dependence are explained well in terms of the subgap density of states of the one-dimensional electronic bands induced by the quantum vibration of Cl ions of the breathing mode. Both substances are found to have a dimensionless electron-phonon coupling constant of λ≊1.2, the zero-temperature gap parameter of (Formula presented)≊1.45 eV, and the transfer integral of (Formula presented)≊0.4 eV. Because of the strong electron-phonon coupling the temperature dependence of the energy gap is dominated by the self-energy effect; even at 0 K the self-energy amounts to 0.07-0.08 eV, being considerably greater than the self-energies in usual semiconductors. The role of the anharmonicity of the chainlike Pt-Cl bonds is discussed in relation to the origin of the large gap parameter.

Original language | English |
---|---|

Pages (from-to) | 2390-2396 |

Number of pages | 7 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 54 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1996 Jan 1 |

Externally published | Yes |

## ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics