Nanostructuring compatibilizers of block copolymers for organic photovoltaics

Abstract

The performance and stability of organic photovoltaic (OPV) devices based upon bulk heterojunction blends of donor and acceptor materials have been shown to be highly dependent on the morphology of the active layer. Block copolymers, which naturally self-assemble into periodic ordered nanostructures, can be utilized in diverse ways to control morphology on a length scale relevant for charge separation, recombination and transportation, which makes them promising candidates for high performance and thermally stable OPV devices. This minireview presents a brief statistical discussion of inter-study correlations and a summary of past interfacial research on block copolymer nanostructuring compatibilizers for OPVs.

Tackling Performance Challenges in Organic Photovoltaics: An Overview about Compatibilizers

“…The declared purposes of the present review are several: (i) to underline and advertise the importance of a single unambiguous definition of CBs, thus helping researchers to focus on this research field and prevent the future literature from becoming fragmentary; (ii) to offer a broad survey over the last decade reports, in order to reveal the growth in compatibilizers studies and underline the current trends, as well as some investigations which rapidly lost interest; and (iii) to update what already under the lens in some previous reviews, which are incomplete just due to the rapid shift forward of scientific research. Related to the last point, some reviews are warmly recommended as sources of historical information for the thoroughness of the specific topic therein discussed [116][117][118][119]; these last two reviews were an important source of information [120,121], and a further stimulus to bring a clear and well-defined definition of compatibilizers to the general audience and provide a useful guideline in the investigation of this fertile field of research. The central part of the review is Section 2, where compatibilizers are discussed and classified accordingly to their polymeric or molecular nature.…”

Copolymers and Hybrids Based on Carbazole Derivatives and Their Nanomorphology Investigation

“…The introduction of various functional units onto semiconducting polymers, either as side chains or at the α- and/or ω- end positions of the polymeric chains, allows a variety of approaches for the formation of complex macromolecular architectures or even hybrid structures. Such modifications on the semiconducting polymeric chains enable the covalent attachment of a semiconducting polymer onto carbon nanostructures, creating hybrid materials that are expected, and in many cases have indeed revealed, combined properties, altering and fine-tuning the morphology and nanophase separation of the pure component blends [ 25 , 26 , 27 , 28 , 29 , 30 ]. Another approach for the formation of hybrid structures is the development of non-covalent interactions between a molecular dispersant (in most cases a pyridine unit) and fullerene species.…”

Morphology stabilization strategies for small-molecule bulk heterojunction photovoltaics

“…a block co-polymer), which is included in the active layer during device fabrication. [31][32][33][34][35][36] Donor-acceptor block-copolymers can be envisioned as a single active component for truly thermodynamically stable polymer BHJs. [37][38][39][40] Despite the interest in developing strategies for stabilization of polymer-based devices, few reports have addressed morphological stability in small-molecule BHJs even though this is reasonably a greater challenge, due to the relatively high crystallinity in small molecule semiconductors and the absence of polymer entanglement, which leads to negligible mixing between the donor and acceptor.…”