Poly(N-isopropylacrylamide-co-methacrylic acid) Interfacial Layer for Efficient and Stable Inverted Organic Solar Cells
- 주제(기타) Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
- 설명문(일반) [Cho, Jung Eun; Son, Serin] Ewha Womans Univ, Grad Sch Educ, Seoul 03760, South Korea; [Kim, Saeah; Kim, Myung Hwa] Ewha Womans Univ, Dept Chem, Seoul 03760, South Korea; [Yang, Jeehye; Kang, Moon Sung] Soongsil Univ, Dept Chem Engn, Seoul 06978, South Korea; [Eom, Seung Hun; Yoon, Sung Cheol] Korea Res Inst Chem Technol, Div Adv Mat, Daejeon 34114, South Korea; [Kim, BongSoo] Ulsan Natl Inst Sci & Technol, Dept Chem, Ulsan 44919, South Korea
- 등재 SCIE, SCOPUS
- 발행기관 AMER CHEMICAL SOC
- 발행년도 2019
- URI http://www.dcollection.net/handler/ewha/000000160153
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/acs.jpcc.8b10871
초록/요약
One of the key components in inverted organic solar cells is a zinc oxide (ZnO) layer as an electron-extraction layer. However, this layer contains electron traps that decrease the electron-extraction efficiency and reduce the photovoltaic performance. In this work, we report the photovoltaic property improvement of inverted PTB7-Th:PC71BM solar cells by coating high-molecular-weight poly(N-isopropylacrylamide-co-methacrylic acid) (H-PNIPAM) on top of the ZnO layer. The H-PNIPAM film thicknesses were carefully controlled by spin-coating different concentrations of H-PNIPAM solutions to generate an optimal thickness (3-5 nm). Atomic force microscopy and X-ray photoelectron spectroscopy revealed a uniformly coated H-PNIPAM layer. The photoluminescence spectra showed that the layer reduced the number of ZnO trap states. Contact angle measurements indicated that the layer modified the ZnO surface to become more hydrophobic, resulting in good contact with photoactive films. At the same time, the treatment decreased the work function of the ZnO layer from 4.12 to 3.82 eV. Moreover, electron mobility measurements indicated that the use of the H-PNIPAM layer increased the electron mobility in the photoactive layer. Furthermore, the use of the H-PNIPAM layer maintained the initial performance over a long period of time (>3000 h) and improved the photovoltaic performances of other devices based on the photoactive layer (PBDB-T:ITIC and PV-D4610:PC71BM). This work conclusively demonstrates that our new H-PNIPAM is a promising surface modifier of the electron-transporting ZnO layer.
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