期刊
ADVANCED FUNCTIONAL MATERIALS
卷 24, 期 44, 页码 6989-6998出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201401367
关键词
non-fullerene acceptors; solar cells; bulk heterojunctions; organic photovoltaics; exciton diffusion length
类别
资金
- National Science Foundation [DMR-1035480, DGE-1144085]
- Office of Naval Research
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]
Organic solar cells utilizing the small molecule donor 7,7-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b]dithiophene-2,6-diyl)bis(6-fluoro-4-(5-hexyl-[2,2-bithiophen]-5-yl)benzo[c][1,2,5] thiadiazole) (p-DTS(FBTTh2)(2) and the polymer acceptor poly{[N,N-bis(2-octyldodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl]-alt-5,5-(2,2-bithiophene)}(P(NDI2OD-T2)) are investigated and a power conversion efficiency of 2.1% is achieved. By systematic study of bulk heterojunction (BHJ) organic photovoltaic (OPV) quantum efficiency, film morphology, charge transport and extraction and exciton diffusion, the loss processes in this blend is revealed compared to the blend of [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) and the same donor. An exciton diffussion study using Forster resonant energy transfer (FRET) shows the upper limit of the P(NDI2OD-T2) exciton diffusion length to be only 1.1 nm. The extremely low exciton diffusion length of P(NDI2OD-T2), in combination with the overlap in donor and acceptor absorption, is then found to significantly limit device performance. These results suggest that BHJ OPV devices utilizing P(NDI2OD-T2) as an acceptor material will likely be limited by its low exciton diffusion length compared to devices utilizing functionalized fullerene acceptors, especially when P(NDI2OD-T2) significantly competes with the donor molecule for photon absorption.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据