전도성 고분자 내에 분자 내 및 분자 간 첨가제 도입으로 인한 광전효과의 향상에 관한 연구

Abstract

Bulk hetero junction (BHJ) polymer solar cell (PSCs) is one of the most promising field as alternative energy source. Organic photovoltaic cells(OPVs) based on donor: acceptor types continue to be of interest as promising candidates of low-cost renewable energy that convert sunlight into electricity due to their possibility for solution processing and high-throughput roll-to-roll manufacturing. In the first part, 2,2,3,3,4,4,4-Heptafluoro-N-phenyl-butyr- amide (F-ADD) was synthesized as a novel composition gradient inducer for a blend of P3HT and PC60BM. Due to the advantages of P3HT, i.e. high crystallinity that can make a high hole mobility and relatively easy synthesis, many researchers have studied the OPVs by using this material until a recent times. However, the conventional method to prepare blend film is incomplete in the vertical profile which stands chance of lowering the PCE. In reality, Jo et al, they mathematically analyzed the photovoltaic photovoltaic properties of OPVs with several vertical composition distributions in P3HT:PCBM system by using a computational viewpoint. F-ADD was able to vertically modulate chemical distribution in the blend by controlling the surface energy due to the selective interaction of F-ADD with PC60BM. The vertically even distributed nanostructure had more interfacial areas, thus smaller domain sizes, leading to a short exciton diffusion length. This resulted to the better photovoltaic performance (PCE = 3.2 → 4.4 %). of the copolymer and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM).In the second part, In organic solar cell, PCDTBT is one of most promising material. But it has low solubility and film formability. So Improving those properties, we used alkoxy DTBT, as an acceptor instead of DTBT. This alkoxy DTBT has alkoxy on benzothiazole, but this chain can reduce HOMO level of conjugated polymer which can influence of high Voc. And additionally we introduced small amount of 3,6-carbazole to alkoxy-PCDTBT. In previous our work, we report small amount of incorporated 3,6 carbazole in PFDTBT can improve hole mobility. Due to enhanced hole mobility, we could get enhanced Jsc, FF, PCE. So In this work, I make new alkoxy-PCDTBT with small amount of 3,6 carbazole. So In this paper, we could get enhanced power conversion efficiency (3.8 to 4.9%) without any interlayer of special process.