Photoluminescence of MEH-PPV with ultraviolet excitation |
| |
Authors: | Marcelo M. Faleiros Paulo B. Miranda |
| |
Affiliation: | Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, São Carlos, São Paulo 13560-970, Brazil |
| |
Abstract: | The basic optical properties of PPV-based polymers have been extensively studied due to their potential technological applications. However, a detailed investigation of electronic processes following photoexcitation in the ultraviolet is still lacking. We report photoluminescence measurements on poly(1-methoxy-4-ethylhexyloxy-paraphenylenevinylene) – MEH-PPV in the 2.0–5.6 eV range, with excitation up to 5.6 eV. The photoluminescence spectra lineshape is independent of excitation energy. The photoluminescence efficiency is high for energies well below the absorption maximum due to near-resonant excitation of the longest conjugated segments which are responsible for the PL. It decreases strongly for excitation energies in the range 2.1–2.5 eV (up to the absorption maximum) and slightly from 2.5 to 5.6 eV. The results indicate that states excited in the ultraviolet rapidly relax nonradiatively to the lowest state, from where the usual luminescence occurs. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|