From Event: SPIE Organic Photonics + Electronics, 2018
It is established that the nanomorphology plays an important role in performance of bulk-heterojunction (BHJ) organic solar cells. From intense research in polymer-fullerene systems, some trends are becoming apparent. For example, small ~10 nm domains, high crystallinity, and low miscibility are typically measured in high-performance systems. However, the generality of these concepts for small-molecule (SM) BHJs is unclear. We present a comprehensive study of performance, charge generation and extraction dynamics, and nanomorphology in SM-fullerene BHJ devices to probe these critical structure-property relationships in this class of materials. In the systems investigated, small domains remain important for performance. However, devices composed of highly mixed domains with modest crystallinity outperform those consisting of pure/highly crystalline domains. Such a result points to an alternative ideal morphology for SM-based devices that involves a predominant mixed phase. This stems from SM aggregation in highly mixed domains that both maximize interface for charge generation and establish continuous pathways for efficient charge extraction. Such a morphological paradigm should be considered in future SM systems in pursuit of high-efficiency large-scale solar power production.
Brian A. Collins, Obaid Alqahtani, Maxime Babics, Julien Gorenflot, Victoria Savikhin, Thomas Ferron, Ahmed Balawi, Andreas Paulke, Zhipeng Kan, Michael Pope, Andrew J. Clulow, Jannic Wolf, Paul L. Burn, Ian R. Gentle, Dieter Neher, Michael F. Toney, Frédéric Laquai, and Pierre M. Beaujuge, "Mixed domains enhance charge generation and extraction in small-molecule bulk heterojunction solar cells (Conference Presentation)," Proc. SPIE 10737, Organic, Hybrid, and Perovskite Photovoltaics XIX, 107370F (Presented at SPIE Organic Photonics + Electronics: August 22, 2018; Published: 18 September 2018); https://doi.org/10.1117/12.2321965.5836584347001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 18,000 conference presentations, including many plenaries and keynotes.