Improving the Compatibility of Donor Polymers in Efficient Ternary Organic Solar Cells via Post-Additive Soaking Treatment

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• 作者：Xiaoyu Yang ; Fei Zheng ; Weilong Xu ; Pengqing Bi ; Lin Feng ; Jianqiang Liu ; Xiaotao Hao
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：9
• 期：1
• 页码：618-627
• 全文大小：624K
• ISSN：1944-8252

文摘

In dual-donor ternary organic solar cells, the compatibility between the donor polymers plays important roles to control the conformational change and govern the photophysical behavior in the blend films. Here, we apply a post-additive soaking (PAS) approach to reconstruct the morphology in a ternary organic photovoltaic BHJ of PTB7-Th: PCDTBT: PC₇₁BM. The PAS-treated device has a maximum power conversion efficiency (PCE) of about 8.7% in this ternary system. From the analyses of GIWAXS and GISAXS, the superior device performance is attributed to the favorable nanomorphology with optimum crystallinity of PTB7-Th and good intermixing of PCDTBT with PTB7-Th:PC₇₁BM, leading to improved charge transport in the vertical direction. AFM and TRPL measurements clearly demonstrate PAS-treated film envisages a homogeneous distribution of smaller PC₇₁BM aggregates to facilitate the exciton dissociation and carrier extraction at the interface. The increased PCE ascribed to not only the enhancement of absorption and nonradiative Förster resonance energy transfer (FRET) between two donors (PCDTBT and PTB7-Th) but also the formation of a bicontinuous interpenetrating network of PC₇₁BM.