Effective protection of sequential solution-processed polymer/fullerene bilayer solar cell against charge recombination and degradation
- 주제(키워드) Bilayer solar cell , Charge recombination , Organic solar cell , TiO<inf>2</inf> interlayer
- 등재 SCIE, SCOPUS
- 발행기관 Elsevier
- 발행년도 2015
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000118262
- 본문언어 영어
- Published As http://dx.doi.org/10.1016/j.orgel.2015.06.039
- 저작권 이화여자대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Abstract Both charge recombination and degradation in sequential solution processed polymer/fullerene bilayer organic photovoltaics (OPV) are effectively reduced by the insertion of a TiO<inf>2</inf> inter-layer between the bilayer and Al electrode. The polymer/fullerene bilayer composed of a poly(3-hexylthiophene) (P3HT) bottom-layer and a [6,6] phenyl C61-butyric acid methyl ester (PCBM) top-layer shows significant change in morphology due to the substantial inter-penetration of P3HT and PCBM during the thermal annealing process. Consequently, the bilayer surface becomes P3HT rich resulting in significant charge recombination at the bilayer/Al interface of the bilayer OPV. The charge recombination rate of the bilayer OPV is reduced by one order of magnitude upon the insertion of a TiO<inf>2</inf> nanoparticle inter-layer between the bilayer and the Al electrode after the thermal annealing process. In contrast, when the thermal annealing process is conducted after insertion of the inter-layer, the effect of the TiO<inf>2</inf> inter-layer becomes insignificant. The V<inf>OC</inf> and efficiency of the bilayer OPV is greatly enhanced from 0.37 to 0.66 V and 1.2% to 3.7%, respectively by utilizing the properly constructed TiO<inf>2</inf> inter-layer in the bilayer OPV. Additionally, insertion of the TiO<inf>2</inf> inter-layer significantly improves the stability of the bilayer OPV. The bilayer OPV with a TiO<inf>2</inf> inter-layer maintains 51% of its initial PCE after storage under dark ambient conditions for 700 h without encapsulation, whereas the bilayer OPV without a TiO<inf>2</inf> inter-layer did not show any solar cell performance after 200 h under the same conditions. © 2015 Elsevier B.V.
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