Block copolymer morphologies in dye-sensitized solar cells: probing the photovoltaic structure-function relation

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Dye-sensitized solar cells (DSSCs) are a promising photovoltaic technology.
• Efficient charge transport and large surface areas are crucial for high-performance DSSCs.
• Current mesoporous nanoparticle films present limitations in optimizing these factors.

Purpose of the Study:

• To integrate ordered mesostructured titania arrays into DSSCs.
• To investigate the impact of different morphologies (1D columnar vs. 3D gyroid) on solar cell performance.
• To compare the performance of these mesostructures with state-of-the-art nanoparticle films.

Main Methods:

• Replication of ordered, oriented one-dimensional (1D) columnar and three-dimensional (3D) bicontinuous gyroid block copolymer phases using titania.
• Fabrication of dye-sensitized solar cells incorporating these mesostructured titania arrays.
• Characterization of solar cell performance, including charge transport and recombination dynamics.

Main Results:

• Faster charge transport was observed in 1D titania "wires" compared to 3D gyroid arrays.
• 1D wire arrays exhibited structural instability and limited surface area, hindering performance.
• The 3D gyroid titania morphology significantly outperformed current state-of-the-art mesoporous nanoparticle films.

Conclusions:

• Ordered mesostructured titania arrays, particularly the 3D gyroid morphology, offer a viable alternative to nanoparticle films in DSSCs.
• The gyroid structure provides a balance of efficient charge transport pathways and high surface area, leading to enhanced solar cell performance.
• Further research into improving the structural stability of 1D architectures could unlock their potential.