Abstract
We explore two small molecules containing arms of dicyano-n-hexylrhodanine and diathiafulvalene wings terminated with benzothiadiazole linker, denoted as BAF-4CN and BAF-2HDT, respectively, as small molecule non-fullerene acceptors (SMNFAs) in organic solar cells. The proposed materials are mixed with a low band gap polymer donor PTB7-Th having broad absorption in the range of 400–750 nm to form solution-processed bulk heterojunctions (BHJs). The photoluminescence (PL) measurements show that both donor and acceptor can quench each other’s PL effectively, implying that not only electrons are transferred from PTB7-Th → SMNFAs but also holes are transferred from SMNFAs → PTB7-Th for efficient photocurrent generation. Furthermore, solvent vapor annealing (SVA) processing is shown to yield a more balanced hole and electron mobility and thus suppresses the trap-assisted recombination significantly. With this dual charge transfer enabled via fine-tuning of end-groups and SVA treatment, power conversion efficiency of approximately 10% is achieved, demonstrating the feasibility of the proposed approach.
Highlights
Significant drawbacks such as weak absorption in the visible region of the solar spectrum, high production cost, wide band gap, the difficulty of synthesis and purification and low open circuit voltage (Voc)[12]
We have studied the photovoltaic performance of the acceptors in bulk heterojunctions (BHJs) inverted structure solar cell blending with BDT-based π-electron rich conjugated polymer donor PTB7-Th, commonly known as PCE10 or, PBDTTT-EFT30,31
In order to improve the device performance further, we have investigated the effect of vacuum annealing (VA) and solvent vapor annealing (SVA) treatments on the blend films[27,28]
Summary
Annealing over Thermal Annealing on the Photovoltaic Performance of Received: 9 July 2018 Accepted: 23 April 2019 Published: xx xx xxxx. A very high film thickness (~300 nm) of the photoactive layer is required to fabricate devices[29] These requirements are so stringent that it is not so easy to achieve high PCE from the PffBT4T-2OD based OPV devices and there are only a few reports on the PffBT4T-2OD:PC70BM based OSCs. These requirements are so stringent that it is not so easy to achieve high PCE from the PffBT4T-2OD based OPV devices and there are only a few reports on the PffBT4T-2OD:PC70BM based OSCs In this communication, we have studied the photovoltaic performance of the acceptors in BHJ inverted structure solar cell blending with BDT-based π-electron rich conjugated polymer donor PTB7-Th, commonly known as PCE10 or, PBDTTT-EFT30,31. Fluorine atom on TT unit is normally introduced to achieve low-lying highest occupied molecular orbital (HOMO) and LUMO energy levels[32,33]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
