Enhanced photovoltaic performances via ternary blend strategy employing a medium-bandgap D-A type alternating copolymer as the single donor. (1st May 2019)

• Record Type: Journal Article
• Authors: Chen, Yunxiang; You, Guofeng; Zou, Ding; Zhuang, Qixin; Zhen, Hongyu; Ling, Qidan
• Is Part Of: Solar energy. Volume 183(2019)
• Page Start: 350
• Page End: 355
• Publication Date: 2019-05-01
• Subjects: Polymer solar cells -- Ternary blend strategy -- Complementary absorption -- Optimized morphology; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2019.03.029
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: POBDFBT presents good miscibility with different acceptors, and the optimal nanometer-scale phase-separation endows the ternary PSCs superior device performances. Highlights: A novel polymeric donor is developed from the BDT-FBT alternating copolymers. Short-circuit current density of the PSCs is enhanced significantly via ternary blend strategy. The optimized ternary PSCs present a peak PCE of 7.91%. Abstract: In this work, a medium-bandgap polymer POBDFBT was synthesized and served as the single donor in binary and ternary polymer solar cells (PSCs) together with two acceptors (ITIC and PC71 BM). A promising power conversion efficiency (PCE) of 7.91% with a high short-circuit current density ( JSC ) of 17.65 mA cm −2 is achieved from the ternary PSC without any cathode modification layer. The enhancement of JSC in ternary PSCs can be attributed to the complementary absorption and cascade-like energy level of the two acceptors. With alkoxyl substitution in the electron-donating unit, POBDFBT presents good miscibility with ITIC and PC71 BM respectively, while a more optimized morphology of the ternary bulk heterojunction (BHJ) lead to the enhanced and balanced hole/electron mobility of the devices. Our results demonstrate a facile method for developing new polymeric donors for serving as the universal donors in binary and ternary PSCs.