Room temperature processed polymers for high-efficient polymer solar cells with power conversion efficiency over 9%. (July 2017)

• Record Type: Journal Article
• Authors: Liao, Xunfan; Zhang, Lin; Chen, Lie; Hu, Xiaotian; Ai, Qingyun; Ma, Wei; Chen, Yiwang
• Is Part Of: Nano energy. Volume 37(2017:Jul.)
• Page Start: 32
• Page End: 39
• Publication Date: 2017-07
• Subjects: Room temperature processing -- Organic solar cells -- Temperature-dependent aggregation -- Domain purity -- Random polymerization; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2017.05.008
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Although the family of difluoro-2, 1, 3-benzothiadiazole with 2-octyldodecyl alkyl chains based donor copolymers have reached over 10% power conversion efficiencies (PCE) in past three years, several limitations are holding back their further commercialization application. For instance, those polymers have to be processed at a high temperature (~110 °C) due to their strong aggregation in the solution. Here we report the achievement of low temperature-processed polymers for high-efficient polymer solar cells (PSCs) via random polymerization. The introduction of 2, 2′-(perfluoro-1, 4-phenylene)dithiophene (2TPF4) via random polymerization can weaken the strong self-aggregation of the polymers, enabling the polymers processible by spin-coating at room temperature as well as favor the formation of a near ideal active layer morphology which involves highly crystalline yet with reasonably small polymer domains. All these three polymers exhibit preferable face-on orientation and the domain purity could be significantly changed by the introduction of 2TPF4 block. A superior PCE of 9.4% of the photovoltaic device based on PffBT-2TPF4-9/1 was obtained, which is one of the best values for room temperature-processed solar cells. These findings indicate that low temperature processed high-efficient PSCs can be achieved by rational conjugated backbone engineering, which presents distinctive advantages for largescale production in the near future. Graphical abstract: Three room temperature-processed polymers are synthesized and applied for polymer solar cells with a high power conversion efficiency of 9.4%. Highlights: The room temperature-processed copolymers are synthesized for polymer solar cells. The PffBT-2TPF4 based polymer solar cell achieve 9.4% power conversion efficiency. The typical aggregation is studied by temperature-dependent absorption spectra. GWAXS and R-SoXS are utilized to investigate the microstructure of the blends. The room temperature-processed polymers are attractively for industrial processing.