High-Performance NIR Organic Photodetectors using NIR-Absorbing Non-Fullerene and Conjugated Polymer Acceptors
- 주제(키워드) Near-Infrared , Organic Photodetectors , Non-Fullerene Acceptors , All-Polymer Photodetectors , Conjugated Polymer Acceptors
- 주제(DDC) 547
- 발행기관 아주대학교
- 지도교수 김종현
- 발행년도 2023
- 학위수여년월 2023. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000032602
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Organic photodetectors (OPDs) have been studied in the near-infrared (NIR) region with various applications. NIR OPDs based on non-fullerene acceptors (NFAs) and conjugated polymer (CP) acceptors can be adjusted electronic and morphology properties by designing molecular structures to develop efficient OPDs. In this study, we investigated the effects of central core and functional group substitutions. Four types of NFAs used in NFA OPDs are OH and OCN based on dithieno[3,2-b:2′,3′-d]pyran (DTP) core, and SH and SCN based on dithieno[3,2-b:2′,3′-d]thiopyran (DTTP) core, which enhance the intramolecular charge transfer (ICT) property and responsivity. In addition, OCN and SCN were introduced cyano (CN) substituents to OH and SH, respectively. NFA OPDs based on OCN and SCN with PTB7-Th have small energetic disorder and face-on orientation, which has effective charge transport in the vertical devices and suppressed bimolecular recombination. SCN-based NFA OPD have high specific detectivity (over 10E+12 Jones at −0.5 V in the range from 400 to 1100 nm) from low dark current and increased photocurrent. Furthermore, two polymer acceptors used in all-PPDs are PD-T-Qx2CN and PD-T-FQx2CN, which were modified with CN and Fluorine (F) substituents from PD-T-Qx as p-type CP based on diketopyrrolopyrrole (DPP) and quinoxaline (Qx), and thiophene. All-PPD base on PD-T-FQx2CN with P3HT increased in crystallinity and decreased in the trap density and energetic disorder, thereby suppressing considerably the dark current and increasing the charge carrier mobility. All-PPD based on PD-T-FQx2CN exhibited higher responsivity and specific detectivity (1.71E-2 A/W and 1.18E+12 Jones at −0.5 V, 860 nm) than that based on PD-T-Qx2CN (8.79E-3 A/W and 3.27E+11 Jones at −0.5 V, 860 nm). As shown in this study, CN and F substitution of conjugated backbone can be performed to prepare an acceptor for NIR OPDs.
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