Observation of the lowest Ag excited state lying in the optical gap in polydiacetylene by means of second-harmonic generation spectroscopy

被引：14

作者：

Manaka, T ^{[1
]}

Yamada, T ^{[1
]}

Hoshi, H ^{[1
]}

Ishikawa, K ^{[1
]}

Takezoe, H ^{[1
]}

机构：

[1] Tokyo Inst Technol, Dept Organ & Polymer Mat, Meguro Ku, Tokyo 152, Japan

来源：

SYNTHETIC METALS | 1998年 / 95卷 / 02期

关键词：

second-harmonic generation spectroscopy; polydiacetylene; forbidden excited state;

D O I：

10.1016/S0379-6779(98)00053-8

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have observed second-harmonic generation (SHG) spectra in polydiacetylene (poly [5,7-dodecadiyne-1,12-diyl-bis-ethylurethane], PDA-4U2 for short) films of red and blue forms. In addition to resonant peaks located at the high-energy side of the main absorption peak, a new resonant peak was observed at the lower-energy side of the absorption peak in blue-form PDA-4U2. In contrast, in red-form PDA-4U2, the SHG resonance peak position in the lower-energy side coincides with the absorption peak position. The resonance enhancement of SHG originates from the electric-quadrupole transition to the dipole-forbidden state. The lowest resonance peak observed in the blue-form PDA-4U2 strongly suggests the existence of the lowest A(g), excited state lying below the lowest B-u, excited state. (C) 1998 Elsevier Science S.A. All rights reserved.

引用

页码：155 / 158

页数：4

共 22 条

[1] EXCITON VERSUS INTERBAND ABSORPTION IN PEIERLS INSULATORS [J].