박막모폴로지와 전하 재결합이 다이케토피롤로피롤 기반 고분자 근적외선 포토디텍터의 성능에 미치는 영향에 대한 연구
Effect of morphology and charge recombination on the performance of diketopyrrolopyrrole-based polymer near-infrared photodetectors
- 주제(키워드) near-infrared photodetector , conjugated polymers , bulk heterojunction , morphology , charge recombination , dark current
- 발행기관 아주대학교
- 지도교수 김종현
- 발행년도 2019
- 학위수여년월 2019. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000028351
- 본문언어 한국어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Near-infrared (NIR) photodetectors sensitive to 860 nm were fabricated through a solution process with two different conjugated polymers (CPs) sharing a similar conjugated backbone consisting of the diketopyrrolopyrrole (DPP) moiety. The two CPs had comparable conjugated nature, but their detection capability was significantly distinguished by the applied linker units, thiophene for PDPP-T and fluorinated thiophene for PDPP-FBT. First, it has been revealed that employing additive during active film preparation is beneficial to achieve optimum film morphology for both CPs, which can suppress dark current and provide enhanced detectivity. In addition, when a highly electronegative fluorine atom that induces a surface dipole was introduced into the conjugated skeleton, it has been clearly demonstrated by transient photovoltage measurement that the charge recombination time is lengthened, which implies the increase of possibility of charge extraction in actual device through reducing the charge recombination. Thus, PDPP-FBT exhibited higher external quantum efficiency and responsivity overall wavelength. Our results indicate that the management of both film morphology and surface dipole of CP are evenly important to achieve high detectivity and responsivity in organic NIR photodetectors.
more