Abstract
Carrier generation dynamics in binary PTB7-Th:COi8DFIC (1:1.5) and ternary PTB7-Th:COi8DFIC:PC71BM (1:1.05:0.45) composites were investigated to identify the origins of high power conversion efficiencies (PCEs) in ternary bulk-heterojunction (BHJ) organic solar cells. Steady-state photoluminescence and time-resolved photoinduced absorption spectroscopic analyses revealed that the ternary composite exhibited faster hole transfer from COi8DFIC to PTB7-Th (8 ps compared to 21 ps in the binary composite), which led to an improved exciton separation yield in COi8DFIC (94% compared to 68% in the binary composite). Improved intermixing of the component materials and efficient electron transfer from COi8DFIC to PC71BM facilitated enhancement in the hole transfer rate. The COi8DFIC-to-PC71BM electron transfer promoted an electron transport cascade over PTB7-Th, COi8DFIC, and PC71BM, which efficiently deactivated back-electron transfer (carrier recombination loss) from COi8DFIC to PTB7-Th at ∼160 ps and assisted in improving the PCE of the ternary BHJ cell (13.4% compared to 10.5% in the binary BHJ cell).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
