Publications by authors named "Timothy S Gehan"

Organic-nanoparticle-based solar cells have drawn great attention due to their eco-friendly and environmentally friendly fabrication procedure. However, these surfactant-stabilized nanoparticles suffer open-circuit voltage loss due to charge trapping and poor extraction rate at the polymer cathode interface. Here, we have investigated the origin of voltage loss and charge trapping in surfactant-stabilized nanoparticle-based devices.

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Article Synopsis
  • Binary polymer nanoparticle glasses allow for the controlled assembly of different components, enabling the creation of functional materials at both nanoscale and mesoscale levels.
  • The research shows that by adjusting the proportions of semiconducting and insulating nanoparticles, the electrical conductivity can be finely tuned, with percolation thresholds ranging from 24% to 30%.
  • A resistor network model developed in the study helps to replicate the experimental results and foresee percolation trends, while also analyzing the cluster statistics of these nanoparticle glasses to aid in material design.
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We address here the need for a general strategy to control molecular assembly over multiple length scales. Efficient organic photovoltaics require an active layer comprised of a mesoscale interconnected networks of nanoscale aggregates of semiconductors. We demonstrate a method, using principles of molecular self-assembly and geometric packing, for controlled assembly of semiconductors at the nanoscale and mesoscale.

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Charge transport through a semiconducting nanoparticle assembly is demonstrated. The hole mobility of low and high molecular weight and regioreglular poly(3-hexylthiophene) (P3HT) nanoparticles is on the order of 2 × 10(-4) to 5 × 10(-4) cm(2) V(-1) s(-1) , which is comparable to drop-cast thin films of pristine P3HT. Various methods are employed to understand the nature and importance of the nanoparticle packing.

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