Electrospun Conjugated Polymer/Fullerene Hybrid Fibers: Photoactive Blends, Conductivity through Tunnelling-AFM, Light-Scattering, and Perspective for Their Use in Bulk-Heterojunction Organic Solar Cells

TL;DR

This study develops electrospun conjugated polymer/fullerene hybrid fibers with unique morphology and optical properties, aiming to improve charge transport and light absorption in bulk-heterojunction organic solar cells.

Contribution

It introduces a novel electrospinning method to create nanofibrous hybrid fibers with enhanced interfaces and light-scattering properties for solar cell applications.

Findings

Fibers exhibit ribbon-shaped morphology and form a network suitable for active layers.

Homogeneous charge transport and effective exciton dissociation are observed.

Nanofibrous mats show specific light-scattering properties that may boost photovoltaic efficiency.

Abstract

Hybrid conjugated polymer/fullerene filaments based on MEH-PPV/PVP/PCBM are prepared by electrospinning, and their properties assessed by scanning electron, atomic and lateral force, tunnelling, and confocal microscopy, as well as by attenuated total reflection Fourier transform-infrared spectroscopy, photoluminescence quantum yield and spatially-resolved fluorescence. Highlighted features include ribbon-shape of the realized fibers, and the persistence of a network serving as a template for heterogeneous active layers in solar cell devices. A set of favorable characteristics is evidenced in this way in terms of homogeneous charge transport behavior and formation of effective interfaces for diffusion and dissociation of photogenerated excitons. The interaction of the organic filaments with light, exhibiting specific light-scattering properties of the nanofibrous mat, might also contribute to spreading incident radiation across the active layers, thus potentially enhancing photovoltaic performance. This method might be applied to other electron donor-electron acceptor material systems for the fabrication of solar cell devices enhanced by nanofibrillar morphologies embedding conjugated polymers and fullerene compounds.