Albert-Seifried, Sebastian Ko, Doo-Hyun Huettner, Sven Kanimozhi, Catherine Patil, Satish Friend, Richard H. 2024-01-20T10:02:32Z 2024-01-20T10:02:32Z 2021-09-05 2014-04 1463-9076 https://pubs.kist.re.kr/handle/201004/126917 We report the performance and photophysics of a low band-gap diketopyrrolopyrrole-based copolymer used in bulk heterojunction devices in combination with PC71BM. We show that the short lifetime of photogenerated excitons in the polymer constitutes an obstacle towards device efficiency by limiting the diffusion range of the exciton to the donor-acceptor heterojunction. We employ ultrafast transient-probe and fluorescence spectroscopy techniques to examine the excited state loss channels inside the devices. We use the high boiling point solvent additive 1,8-diiodooctane (DIO) to study the photoexcited state losses in different blend morphologies. The solvent additive acts as a compatibiliser between the donor and the acceptor material and leads to smaller domain sizes, higher charge formation yields and increased device efficiency. English ROYAL SOC CHEMISTRY NANOSCALE MORPHOLOGY EXCITED-STATE ENERGY PHOTOCURRENT ADDITIVES CRYSTALLIZATION ENHANCEMENT PERFORMANCE SEPARATION Efficiency limitations in a low band-gap diketopyrrolopyrrole-based polymer solar cell Article 10.1039/c4cp00485j 1 PHYSICAL CHEMISTRY CHEMICAL PHYSICS, v.16, no.14, pp.6743 - 6752 PHYSICAL CHEMISTRY CHEMICAL PHYSICS 16 14 6743 6752 scie scopus 000333119800046 2-s2.0-84896368288 Chemistry, Physical Physics, Atomic, Molecular & Chemical Chemistry Physics Article NANOSCALE MORPHOLOGY EXCITED-STATE ENERGY PHOTOCURRENT ADDITIVES CRYSTALLIZATION ENHANCEMENT PERFORMANCE SEPARATION