Korea-Japan Joint Symposium: Functional Polymers for Energy Application (English)
발표 구분
초청강연
제목
Effect of polymer aggregation on photovoltaic performance in polymer solar cell
발표자
()
초록
내용
In photovoltaics, photoinduced charge separation (CS) is one of the key steps and a delicate understanding of its mechanism is essential for high performance solar cells. For CS process, it has been revealed that several factors, such as energetics, composites, morphology, and disorder, significantly affect its efficiency.1 We studied the effect of properties of polymer building blocks, their aggregation nature, on CS efficiency and photovoltaic performance with time-resolved electronic spectroscopies. With a series of polymer solar cells (PSC) composed of benzodithiophene-styrylbenzene composite polymer with and without di-cyano groups, which results in aggregating and nonaggregating properties, respectively, it is discovered that excessive intermixing between donor and acceptor leads to ultrafast and very efficient charge generation but increased charge recombination and shorter-lived polarons reduce charge transport capability, resulting in poor photovoltaic performances.