Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7874048 | Synthetic Metals | 2013 | 5 Pages |
Abstract
We designed and synthesized a new low band gap donor-acceptor copolymer (PDTDPP-Oct) composed of alternating dithieno[3,2-b:2â²,3â²-d]thiophene and bis-thienyl-diketopyrrolo[3,4-c]pyrrole units. The polymer films showed a very broad absorption band that extended up to 950 nm. Thermogravimetric analysis revealed good thermal stability and a high glass transition temperature of 128 °C. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the polymer were estimated to be â5.01 and â3.70 eV, respectively. Bulk heterojunction polymer solar cells were fabricated with the structure: ITO/PEDOT:PSS/polymer:PCBM/Al. The introduction of 1,8-octanedithiol as a processing additive to the polymer/PCBM blend solution significantly improved the device performance relative to devices prepared from the blend solution without the additive. This cell gave a short circuit current of â1.8 mA/cm2, an open circuit voltage of 0.60 V, and a fill factor of 0.52, yielding a power conversion efficiency of 0.55%. The performance improvements were mainly attributed to the fine morphology of the blend film.
Related Topics
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Authors
Chun-Young Lee, BongSoo Kim, Kyung Hwan Kim, Youngwoon Yoon, Min Woo Lee, Dong Hoon Choi, Min Jae Ko, Honggon Kim, Doh-Kwon Lee, Kyungkon Kim,