Maqola

Excitation spectrum for ultrafast photogeneration of charged solitons in polyacetylene

Paulo B. MirandaInstitute for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106D. MosesInstitute for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106Alan J. HeegerInstitute for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106Y. W. ParkInstitute for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106

2002en

ABI

Annotatsiya

Ultrafast photoinduced absorption by infrared-active vibrational modes is used to detect charged solitons in oriented trans-polyacetylene. Soliton pairs are photogenerated within \ensuremath{\sim}250 fs with quantum efficiencies $({\ensuremath{\varphi}}_{\mathrm{ch}})$ approaching unity. The excitation spectrum of ${\ensuremath{\varphi}}_{\mathrm{ch}}$ shows an onset at \ensuremath{\sim}1.0 eV with a weak photon energy dependence up to 4.7 eV. The results are consistent with the ultrafast soliton formation predicted by Su and Schrieffer and with the Su-Scrieffer-Heeger threshold of ${2E}_{g}/\ensuremath{\pi}$ for soliton pair production. The recombination dynamics of charged solitons is very fast (initial $\mathrm{decay}<1\mathrm{ps})$ with a modest dependence on the pump photon energy.

Hali tarjima qilinmagan

Identifikatorlar

DOI: 10.1103/physrevb.66.125202

Iqtiboslar va manbalar

2 ta iqtibos0 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar