Investigations on Thermal Transitions in PDPP4T/PCPDTBT/AuNPs Composite Films Using Variable Temperature Ellipsometry

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Organic semiconductors are crucial for optoelectronic devices.
• Understanding thermal transitions in polymer blends is key for device stability.
• Gold nanoparticles can modify material properties through unique interactions.

Purpose of the Study:

• To comprehensively investigate the thermal transitions of PDPP4T and PCPDTBT polymer blends and their gold nanoparticle composites.
• To determine the phase diagrams of these materials using variable temperature spectroscopic ellipsometry (VTSE).
• To explore the influence of gold nanoparticles on the thermal, optical, and structural properties of the polymer films.

Main Methods:

• Variable temperature spectroscopic ellipsometry (VTSE) was employed to study thermal transitions.
• Differential scanning calorimetry (DSC) was used as a reference method.
• Optical properties, surface morphology, and crystallinity were also analyzed.

Main Results:

• Phase diagrams for PDPP4T/PCPDTBT blends and their gold nanoparticle composites were determined for the first time using VTSE.
• Distinct thermal transitions were observed in the thin films, corresponding to pure polymer phases.
• Gold nanoparticle composites exhibited significantly different thermal transitions compared to neat materials, indicating strong polymer-nanoparticle interactions.

Conclusions:

• Gold nanoparticles influence the thermal transitions and improve optical properties and crystallinity of polymer films.
• Localized surface plasmon resonance (LSPR) and passivation effects are hypothesized to be responsible for these observed changes.
• Findings provide insights for designing and optimizing polymer-nanoparticle materials for advanced optoelectronic applications.