Molecular Interactions that Drive Mechanically Durable and Operationally Stable Organic Solar Cells
Abstract
Organic solar cell (OSC) efficiency has now reached 20%, making them commercially viable as deployable power sources. However, they have yet to be widely commercialized due to a number of limitations with the most notable being long term operational stability. OSC degradation can occur through chemical, morphological, and mechanical pathways. With the military target of expeditionary power, there is a need for the solar modules to be lightweight, flexible, stowable, and mechanically resilient. While ultrathin devices or placing fragile layers near a neutral axis are design possibilities, this is not practical for most target military applications such as integration into tents, rucksacks, etc. Thus, it is critical to achieve high strength and tough OSCs capable of handling expected mechanical insults. Importantly, mechanical stability is not independent of chemical and morphological stability, and a comprehensive understanding of the interconnections is necessary to advance OSC technology. Overall research objectives The overall research objective is to establish the fundamental drivers and device designs that enable operationally stable and mechanically durable organic solar cells (OSCs). This will be achieved by (1) determining the role of molecular interactions of the active layers that govern both morphological and mechanical stability, (2) through a systematic understanding of active layer formulations and additives that promote stability, and (3) through optimizing charge transport layer and buffer layer interfaces for adhesion and operational stability. OSC module design including encapsulation that identifies and overcomes common failure pathways for long lived durable solar modules will also be examined.ApproachThis proposal builds on the knowledge foundation of morphological stability and mechanical robustness developed by the Ade and O#Connor groups during the prior ONR OSC funding period. The research plan takes a holistic approach considering active layer formulation, interfaces, and complete modules to ensure research is driven towards practical OSC technology advancement. At same time, the research focusses on fundamental principles to optimize OSC performance. Detailed analysis of molecular interactions, diffusion, thermomechanical properties and mechanical failure mechanisms willbe performed to establish clear correlations and design frameworks. Although the proposed research is fundamental in nature, research will be informed by close collaboration with PolyPV, founded by the PI and H. Ade and currently with ONR phase-II STTR support. Additional partnerships with organic electronic companies including Brilliant Matter and Epishine will provide direct feedback on theresearch activities and milestones. OutcomesThrough this research grant, OSC designs that optimize operational stability, mechanical resilience, and large-scale processing compatibility with be achieved. An improved understanding of the molecular interaction of multi-component active layer formulations that drive performance and stability will be realized. The design of buffer layers that negate interface solar cell performance degradation pathways while improving mechanical resilience will be established.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 24, 2024
- Source ID
- N000142412101
Entities
People
- Brendan O Connor
Organizations
- North Carolina State University
- Office of Naval Research
- United States Navy