Long-Range Excitons in Optical Absorption Spectra of Electroluminescent Polymer Poly(para-phenylenevinylene)

TL;DR

This paper investigates long-range excitons in poly(para-phenylenevinylene) using intermediate exciton theory, revealing their spectral features and implications for photocurrent mechanisms.

Contribution

It introduces a detailed analysis of long-range excitons in PPV and demonstrates the significance of hopping integrals in optical excitations.

Findings

Long-range excitons produce a distinct peak in optical spectra.

The onset of long-range excitons is near the energy gap.

Large hopping integrals are realistic for optical excitation modeling.

Abstract

The component of photoexcited states with large spatial extent is investigated for poly(para-phenylenevinylene) using the intermediate exciton theory. We find a peak due to long-range excitons at the higher-energy side of the lowest main feature of optical spectra. The fact that the onset of long-range excitons is located near the energy gap is related to the mechanisms of large photocurrents measured in such energy regions. We show that a large value of the hopping integral is realistic for characterizing optical excitations.