Improving the Photostability of Small-Molecule-Based Organic Photovoltaics by Providing a Charge Percolation Pathway of Crystalline Conjugated Polymer
- 주제(키워드) organic solar cell , small molecule organic solar cell , stability
- 주제(기타) Polymer Science
- 설명문(일반) [Kim, Jihee; Ryu, Ka Yeon; Kim, Kyungkon] Ewha Womans Univ, Dept Chem & Nano Sci, Seoul 03760, South Korea; [Koh, Chang Woo; Uddin, Mohammad Afsar; Woo, Han Young] Korea Univ, Dept Chem, Seoul 136713, South Korea; [Jang, Song-Rim; Lim, Bogyu] LG Chem, LG Sciencepk, Future Technol Res Ctr, 30 Magokjungang 10 Ro, Seoul 07796, South Korea; [Lim, Bogyu] Korea Res Inst Chem Technol KRICT, Adv Convergent Chem Div, Green Fine Chem Res Ctr, 45 Jongga Ro, Ulsan 44412, South Korea
- 등재 SCIE, SCOPUS
- OA유형 Green Published, gold
- 발행기관 MDPI
- 발행년도 2020
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000175096
- 본문언어 영어
- Published As http://dx.doi.org/10.3390/polym12112598
- PubMed https://pubmed.ncbi.nlm.nih.gov/33167422
초록/요약
Photostability of small-molecule (SM)-based organic photovoltaics (SM-OPVs) is greatly improved by utilizing a ternary photo-active layer incorporating a small amount of a conjugated polymer (CP). Semi-crystalline poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PPDT2FBT) and amorphous poly[(2,5-bis(2-decyltetradecyloxy)phenylene)-alt-(5,6-dicyano-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PPDT2CNBT) with similar chemical structures were used for preparing SM:fullerene:CP ternary photo-active layers. The power conversion efficiency (PCE) of the ternary device with PPDT2FBT (Ternary-F) was higher than those of the ternary device with PPDT2CNBT (Ternary-CN) and a binary SM-OPV device (Binary) by 15% and 17%, respectively. The photostability of the SM-OPV was considerably improved by the addition of the crystalline CP, PPDT2FBT. Ternary-F retained 76% of its initial PCE after 1500 h of light soaking, whereas Ternary-CN and Binary retained only 38% and 17% of their initial PCEs, respectively. The electrical and morphological analyses of the SM-OPV devices revealed that the addition of the semi-crystalline CP led to the formation of percolation pathways for charge transport without disturbing the optimized bulk heterojunction morphology. The CP also suppressed trap-assisted recombination and enhanced the hole mobility in Ternary-F. The percolation pathways enabled the hole mobility of Ternary-F to remain constant during the light-soaking test. The photostability of Ternary-CN did not improve because the addition of the amorphous CP inhibited the formation of ordered SM domains.
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