标题：Förster resonance energy transfer and morphology optimization for high-performance ternary organic photodetectors
作者：Wang, Fei ;Yang, Xiao-Yu ;Niu, Meng-Si ;Feng, Lin ;Hao, Xiao-Tao
作者机构：[Wang, F] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China;[ Yang, X.-Y] School of Ph 更多
通讯作者地址：[Hao, X.-T] School of Physics, State Key Laboratory of Crystal Materials, Shandong UniversityChina;
来源：Organic Electronics: physics, materials, applications
关键词：Förster resonance energy transfer; Morphology; Ternary organic photodetectors
摘要：Aiming at extending the photoresponse range of the photodetectors based on Poly(3-hexylthiophene-2,5-diyl): [6,6]-Phenyl C 71 butyric acid methyl ester (P3HT: PCBM) host system, Poly [(5,6-difluoro-2,1,3-benzothiadiazole-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2’;5’,2’’;5’’,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) with wide spectral response range, proper energy levels and high crystallinity was integrated to fabricate ternary organic photodetectors. The PffBT4T-2OD introduces energy cascade and Förster resonance energy transfer (FRET) effect from P3HT to PffBT4T-2OD, which contributes to the photocurrent generation. Furthermore, PffBT4T-2OD creates films with desirable crystallinity to produce a favorable morphology resulting in the apparent d-spacing decrement of π-π stacking of P3HT: PCBM, which probably increases the intermolecular charge hopping efficiency. The optimal photodetector shows high on/off ratio of 6.7 × 10 4 with a broad spectral response from 300 nm to 800 nm via incorporating 15 wt% PffBT4T-2OD into polymer bulk heterojunction, which is an obvious improvement compared with the 2.6 × 10 4 on/off ratio of P3HT: PCBM. This work indicates that FRET and morphology optimization have a profound effect on photoresponse and electrical properties of organic photodetectors. © 2019 Elsevier B.V.