Charge transport and microstructure in PFO:MEH-PPV polymer blend thin films

Charge transport in TiO2 ÕMEH-PPV polymer photovoltaics

We study the effect of polymer thickness, hole mobility, and morphology on the device properties of polymer-based photovoltaics consisting of MEH-PPV as the optically active layer, TiO2 as the exciton dissociation surface, and ITO and Au electrodes. We demonstrate that the conversion efficiency in these polymerbased photovoltaics is primarily limited by the short exciton diffusion length combin...

Phase-Separation-Induced Surface Patterns in Thin Polymer Blend Films

Atomic force microscopy (AFM), neutron reflection (NR) and secondary ion mass spectroscopy (SIMS) are used to examine phase separation in symmetrically segregating thin polymer blend films (e1000 Å). Phase separation in the film leads to undulations of the liquid-air interface, provided the film is sufficiently thin to suppress surface-directed spinodal decomposition waves. Flattened droplets a...

Charge Transport in Ferroelectric Thin Films

Control of Molecular Ordering, Alignment, and Charge Transport in Solution-Processed Conjugated Polymer Thin Films

Morphology of conjugated polymers is a critical factor that significantly affects intrinsic charge transport characteristics and in turn performance of polymer-based devices. Morphological defects including misaligned crystalline grains and grain boundaries significantly impede efficient charge hopping between transport sites, resulting in degradation of device performance. Therefore, one impor...

Polarization anisotropy of charge transfer absorption and emission of aligned polymer: fullerene blend films