A pyrrolopyridazinedione-based copolymer for fullerene-free organic solar cells

Astrid-Caroline Knall,Heike M A Ehmann,Nadiia Pastukhova,Shuguang Wen,Matiss Reinfelds,Egon Pavlica,Samuel Rabensteiner,Renqiang Yang,Gregor Trimmel,Sebastian Franz Hoefler,Ilie Hanzu,Mathias Hobisch,Thomas Rath,Gvido Bratina

doi:10.1039/d0nj04573j

Abstract

This study deals with the synthesis and thorough characterization of the conjugated polymer T-EHPPD-T-EHBDT, which shows promising performance in polymer/non-fullerene acceptor organic solar cells.

Highlights

5270 Ajdovscina, Slovenia e CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China † Electronic supplementary information (ESI) available: Additional characterization data and information about the determination of the space-charge-limited current (SCLC) charge carrier mobility
In a very recent approach using Non-fullerene acceptors (NFAs), a power conversion efficiencies (PCEs) of 13% could be obtained with a tetrazine containing conjugated polymer (PSFTZ, 4,8bis(5-((2-butyloctyl)thio)-4-fluorothiophen-2-yl)benzo[1,2-b:4,5-b0] dithiophene-alt-3,6-bis(4-octylthiophen-2-yl)-1,2,4,5-tetrazine) in combination with the NFA Y6.7 This already high performance could be even further pushed by adding Pt(Ph)2(DMSO)[2] to reach 16.35%, which was claimed to be due to morphology improvements
The selected synthesis route towards the conjugated polymer T-EHPPD-T-EHBDT led to a polymer with a molecular weight of 10.2 kDa and a dispersity of 1.65

Summary

Introduction

Tetrazine containing copolymers have recently gained interest as potential candidates to be combined with NFAs. Silica gel 60 F254 and aluminium oxide 60 F254 where Eox(Fc) is the oxidation potential of ferrocene.37 2D-GIWAXS measurements of polymer thin films spin coated on silicon substrates were performed on an Anton Paar SAXSpoint 2.0 system equipped with a Dectris 2D EIGER R 1M hybrid photon counting detector with 75 mm[2] pixel size and using Cu Ka radiation at 50 kV and 1 mA, which was point collimated using automated scatterless slits. J–V curves were recorded under illuminated and dark conditions in inert atmosphere using a Keithley 2400 source meter, and a Dedolight DLH400D lamp (100 mW cmÀ2, similar to AM 1.5 G), which was calibrated with a standard reference silicon solar cell (Fraunhofer ISE). The measurement setup was spectrally calibrated with a reference photodiode (Newport Corporation, 818-UV/DB)

Results and discussion

Findings

Conclusion