Scientists have actually made a substantial advancement in polymer solar cell innovation by developing a method to enhance molecular interactions using side-chain engineering. The research study, which highlights the benefits of oligoethylene glycol (OEG)- based side chains, marks a vital action towards more efficient and ecologically friendly solar cells ideal for wearable devices.
Polymer solar batteries, known for their lightweight and versatility, are perfect for wearable gadgets. Yet, their more comprehensive use is impeded by the harmful halogenated solvents required in their production. These solvents posture ecological and health risks, limiting the appeal of these solar batteries. Alternative solvents, which are less poisonous, regrettably, lack the very same solubility, necessitating greater temperatures and extended processing times.
This inefficiency further hinders the adoption of polymer solar cells. Establishing an approach to eliminate the requirement for halogenated solvents might significantly boost the performance of organic solar batteries, making them preferable for wearable innovation.
In a recently published paper, scientists detail how improving molecular interactions in between the polymer donors and the small particle acceptors using side-chain engineering can lower the requirement for halogenated processing solvents.
The paper was just recently released in Nano Research Energy.
” Blend morphology of polymer donors and little molecule acceptors are extremely impacted by their molecular interactions, which can be determined by interfacial energies between the donor and acceptor products. When their surface area stress values are similar, the interfacial energies and molecular interactions between the donors and the acceptors are anticipated to be more favorable,” stated Yun-Hi Kim, a teacher at Gyeongsang National University in Jinju, Republic of Korea. “To boost the hydrophilicity of the polymer donors and reduce molecular demixing, side-chain engineering can be a possible opportunity.”
The Role of Side-Chain Engineering
Side-chain engineering is when a chemical group, called a side chain, is included to the primary chain of a molecule. Scientist thought that including oligoethylene glycol (OEG)- based side chains would improve the hydrophilicity of the polymer donors thanks to the oxygen atoms in the side chains.
A blend of hydrocarbon and hydrophilic oligoethylene glycol (2EG) carried out better than the basic solvent when utilized in PSC production, based upon overall efficiency and thermal stability. Credit: Nano Research Energy, Tsinghua University Press
Differences in the hydrophilicity of the polymer donors and the small molecule acceptors can impact how they interact. With increased hydrophilicity of the polymer donors and improved interactions between them and the small particle acceptors, non-halogenated processing solvents can be used without sacrificing the efficiency of the solar cell. Polymer solar cells made with OEG-based side chains attached to a benzodithiophene-based polymer donor had a greater power conversion effectiveness at 17.7% compared to 15.6%.
Boosted Efficiency and Stability.
In order to compare results, researchers created benzodithiophene-based polymer donors with either an OEG side chain, hydrocarbon side chains, or side chains that were 50% hydrocarbon and 50% OEG. “This elucidated the effect of side-chain engineering on blend morphology and performance of non-halogenated solvent-processed polymer solar cells,” stated Kim. “Our findings show that polymers with hydrophilic OEG side chains can boost the miscibility with small particle acceptors and improve power conversion performance and device stability of polymer solar cells during non-halogenated processing.”.
In addition to improved power conversion effectiveness, the polymer solar batteries with the OEG-based side chains had actually enhanced thermal stability. Thermal stability is vital for scaling polymer solar batteries, so scientists heated them to 120 degrees Celsius and after that compared the power conversion effectiveness. After 120 hours of heating, the polymers with the hydrocarbon side chains had only 60% of their initial power conversion effectiveness and had abnormalities on their surface area, while the mix of hydrocarbon and OEG retained 84% of their initial power conversion effectiveness.
” Our outcomes can offer a helpful guideline for designing polymer donors that produce efficient and stable polymer solar cells utilizing non-halogenated solvent processing,” said Kim.
Reference: “Polymer donors with hydrophilic side-chains making it possible for thermally-stable and efficient polymer solar batteries by non-halogenated solvent processing” by Soodeok Seo, Jun-Young Park, Jin Su Park, Seungjin Lee, Do-Yeong Choi, Yun-Hi Kim and Bumjoon J. Kim, 24 July 2023, Nano Research Energy.DOI: 10.26599/ NRE.2023.9120088.
Other factors consist of Soodeok Seo, Jin Su Park, and Bumjoon J. Kim of the Korea Advanced Institute of Science and Technology; Jun-Young Park and Do-Yeong Choi of Gyeongsang National University; and Seungjin Lee of the Korea Research Institute of Chemical Technology.
The Korea Institute of Energy Evaluation and Planning and the Korean National Research Foundation funded this research study..
Researchers have made a significant improvement in polymer solar cell innovation by establishing a method to enhance molecular interactions using side-chain engineering. With increased hydrophilicity of the polymer donors and improved interactions between them and the small molecule acceptors, non-halogenated processing solvents can be utilized without sacrificing the performance of the solar cell. Polymer solar cells made with OEG-based side chains attached to a benzodithiophene-based polymer donor had a greater power conversion efficiency at 17.7% compared to 15.6%.
In addition to enhanced power conversion performance, the polymer solar cells with the OEG-based side chains had boosted thermal stability. Thermal stability is vital for scaling polymer solar cells, so researchers warmed them to 120 degrees Celsius and then compared the power conversion performance.
