1. Disordered Inorganic/Polymer Nanoparticle Assemblies for Photovoltaic Applications
Kevin Kittilstved (Chemistry) and Dhandapani Venkataraman (Chemistry)
One of the most fundamental criterion for a photovoltaic device is the efficient separation of charges following light absorption to create excitons. The fields of polymer and inorganic solar cells both rely on designing n- and p-type layers and then working hard to organize these possibly immiscible materials into well-ordered structures with defined morphology to form the perfect bulk heterojunction as shown in Fig. 1. Our approach will be to instead use n- and p-type materials composed of inorganic and organic semiconductor nanoparticles that are both smaller than the exciton diffusion lengths in their bulk analogs.
Fig. 1. Schematic representation of binary assemblies of inorganic and polymer semiconductor nanoparticles.
We will prepare new binary nanoparticle superlattices using the general guidelines recently published by the Venkataraman group . The REU students working on this project will implement these design principles to optimize the compatibility of the inorganic nanoparticle surface-capping groups that are expected to play a significant role in controlling the thermodynamics and kinetics of the assembly process.
- Inorganic Semiconductor Nanocrystals: An REU student in the Kittilstved group will synthesize n-type inorganic semiconductor nanocrystals that will serve as the electron conducting material.
- Semiconducting Polymer Nanoparticles: An REU student in the Venkataraman group will prepare p-type semiconducting polymer nanoparticles with nanocrystalline domains for solar absorption and hole transport properties.
- Collaborative Effort: The two REU students will work together to design and optimize methods to prepare binary assemblies with systematic variation of the composition of each component. They will also characterize the assemblies using various physical techniques and electron microscopies.
- L.A. Renna, C.J. Boyle, T.S. Gehan and D. Venkataraman, “Polymer Nanoparticle Assemblies: A Versatile Route to Functional Mesostructures” Macromolecules, 2015, 48, 6353-6368.