Polymer Synthesis for Morphology Control of Organic Solar Cells
Author
Brette, Mathis Mortensen
Term
4. Term
Education
Publication year
2022
Submitted on
2022-06-10
Pages
66
Abstract
Organic solar cells could be a flexible, low-cost alternative to silicon, but they need further improvement to attract commercial interest. A key challenge is that the active layer can change its structure over time (morphological instability). To improve stability, we explored making copolymers that combine donor and acceptor semiconductors in the same chain. We pursued two routes: vinyl and non-vinyl polymerization. For the vinyl route, we completed the first synthetic step toward the monomer needed for a vinyl copolymer. For the non-vinyl route, we carried out a Suzuki cross-coupling (a widely used reaction that links two molecular building blocks) between donor (electron-rich) and acceptor (electron-poor) units, once and twice under emulsion polymerization conditions, aiming to form donor-acceptor polymer particles in the nanometer range. At this small size, these hydrophobic copolymers could potentially be dispersed in water, which is attractive for water-based processing and large-scale manufacturing.
Organiske solceller kan blive et fleksibelt og billigt alternativ til silicium, men teknologien skal forbedres for at tiltrække kommerciel interesse. En central udfordring er, at det aktive lag kan ændre struktur over tid (ustabil morfologi). For at øge stabiliteten undersøgte vi, om man kan syntetisere donor- og acceptor-halvledere sammen som kopolymerer, så begge funktioner findes i samme kæde. Vi arbejdede med to spor: vinyl- og ikke-vinyl-polymerisering. I vinylsporet gennemførte vi det første syntesetrin mod den monomer, der skal bruges til et vinyl-kopolymer. I det ikke-vinyl-baserede spor udførte vi en Suzuki-krydskobling (en velkendt reaktion, der kobler to molekylære byggesten) mellem donor- (elektronrig) og acceptor- (elektronfattig) enheder, både én gang og to gange under emulsionspolymerisering, med målet om at danne donor-acceptor-polymerpartikler i nanometerskala. I denne størrelse kan sådanne hydrofobe kopolymerer potentielt dispergeres i vand, hvilket er interessant for vandbaserede processer og produktion i stor skala.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords