Organic photovoltaics have the potential to be low cost, rugged, flexible, printed conformably on surfaces, and tunable to absorb in certain spectral windows and to be transparent in others. Record research cells have reached 14 percent power conversion efficiency propelled by the advance of non-fullerene acceptors, however, this is still below the Shockley-Queisser theoretical limit of 33 percent. The various contributions to the losses that limit efficiency are understood, but mitigating these losses is difficult in systems with low order and many interfaces. There is an improved understanding of the charge separation processes at the donor acceptor interface, but more work is needed to fully understand the process and allow design of an optimal junction.
Halide perovskite and organic solar cells have the potential to be manufactured with low cost processing methods. Applied research is needed to understand how to form desired active layer morphologies in processes that more closely mimic commercial manufacturing methods. Applied research is also needed to study the stability of organic and hybrid solar cells.
Research Concentration Areas
The basic research program is primarily focused on:
- Developing a better understanding of the photovoltaic processes in organic bulk heterojunction solar cells, including absorption, exciton formation and diffusion, charge separation, and charge transport and collection
- Improving overall power conversion efficiency by first understanding the sources of loss and how to mitigate them
- Such research may necessarily include broad expertise:
- Design and synthesis of new materials
- Multiscale computation
- Device fabrication and optimization
- Morphology characterization
- Spectroscopy
- Possibly some insight into the nature of order at the donor/acceptor interface
In the long term it is envisioned that the design of donors and acceptors will proactively enhance performance by enabling facile formation of domain structure, along with desired packing within the domains and at domain interfaces.
Applied research may include hybrid approaches and is targeted toward understanding how to create desired morphologies in processes that mimic those in commercial manufacturing. Applied research may also include stability studies.
Research Challenges and Opportunities
Basic Research:
- Improved understanding of loss mechanisms in organic solar cells
- Design of active materials for facile formation of desired domain structure, and order within domains and at domain interfaces
- Improved understanding of factors affecting charge separation and recombination
Applied Research:
- Improved understanding of morphology formation during commercially relevant deposition processes
- Improved understanding of inherent stability of organic and hybrid devices
How to Submit
For detailed application and submission information for this research topic, please refer to our broad agency announcement (BAA) No. N0001425SB001.
Contracts: All white papers and full proposals for contracts must be submitted through FedConnect; instructions are included in the BAA.
Grants: All white papers for grants must be submitted through FedConnect, and full proposals for grants must be submitted through grants.gov; instructions are included in the BAA.