TY - JOUR
T1 - Panchromatic small-molecule organic solar cells based on a pyrrolopyrrole aza-BODIPY with a small energy loss
AU - Feng, Ru
AU - Mori, Tatsuya
AU - Yasuda, Takuma
AU - Furuta, Hiroyuki
AU - Shimizu, Soji
N1 - Funding Information:
This work is supported by Grants-in-Aids from JSPS (No. JP22H02064 and JP19H02703 ) and Naohiko Fukuoka Memorial Foundation .
Funding Information:
Electronic absorption spectra were recorded on a JASCO V-770 spectrophotometer. Fluorescence spectra were recorded on a SPEX Fluorolog-3-NIR spectrometer (HORIBA) with a NIR-PMT R5509 photomultiplier tube (Hamamatsu). Absolute fluorescence quantum yields were measured using a Hamamatsu Photonics C9920-03G calibrated integrating sphere system. 1H and 19F NMR spectra were recorded on a JEOL JNM-ECX500 spectrometer (operating at 495.132 MHz for 1H and 465.889 MHz for 19F) using a residual solvent as an internal reference for 1H (δ = 5.32 ppm for CD2Cl2 and δ = 7.26 ppm for CDCl3) and trifluoroacetic acid as an external reference for 19F (δ = −76.55 ppm). High-resolution mass spectrometry was performed on a JEOL LMS-HX-110 spectrometer (FAB mode with 3-nitrobenzyl alcohol (NBA) as the matrix). Cyclic voltammograms and differential pulse voltammograms were recorded on a CH Instrument Model 620 B (ALS) under an argon atmosphere in dichloromethane solution with 0.1 M tetra-n-butylammonium hexafluorophosphate (nBu4N·PF6) as a supporting electrolyte. Measurements were made with a glassy carbon electrode, an Ag/AgCl reference electrode, and a Pt-wire counter electrode. The concentration of the solution was fixed at 0.5 mM, and the sweep rates were set to 100 mV s−1. The ferrocenium/ferrocene (Fc+/Fc) couple was used as an internal standard. Thin-layer chromatography (TLC) was carried out on aluminum sheets coated with silica gel 60 F254 (MERCK). Preparative separations were performed using silica gel column chromatography (KANTO Silica Gel 60 N, spherical, neutral, 40–50 μm). All reagents and solvents used for reactions were of commercial reagent grade and were used without further purification unless noted otherwise. All solvents used in optical measurements were of commercial spectroscopic grade.Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements were performed to estimate the redox properties using 0.5 mM sample solutions in dichloromethane containing 0.1 M nBu4N·PF6 as a supporting electrolyte (Fig. 3). Table 1 summarizes the redox potentials and the experimental HOMO and LUMO energy levels determined from the onset of the first oxidation and reduction waves. Similar reduction potentials of TT-2PPAB (−1.14 and −1.69 V vs. Fc+/Fc) and DFBT-2PPAB (−1.13 and −1.69 V) indicate the PPAB-centered reductions. Meanwhile, the first oxidation potentials of TT-2PPAB and DFBT-2PPAB are slightly changed because of the different donor units (0.21 V for TT-2PPAB, 0.17 V for DFBT-2PPAB). The estimated HOMO energy levels of TT-2PPAB and DFBT-2PPAB at −4.97 and −4.95 eV, respectively, are deeper than that of CPDT-2PPAB at −4.89 eV [32]. This can benefit in enhancing the open-circuit voltage (Voc) values. Estimated electrochemical band gaps are matched well with the trends observed in the optical band gaps.This work is supported by Grants-in-Aids from JSPS (No. JP22H02064andJP19H02703) and Naohiko Fukuoka Memorial Foundation.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2023/2
Y1 - 2023/2
N2 - A small photon energy loss (Eloss) is one of the requisites for achieving near-infrared (NIR) small-molecule organic solar cells (SM-OSCs). Herein, we present two novel pyrrolopyrrole aza-BODIPY (PPAB)-based panchromatic chromophores, TT-2PPAB and DFBT-2PPAB, with an acceptor-donor-acceptor configuration for photovoltaic studies. Among them, in combination with [6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) acceptor, TT-2PPAB exhibits a moderate power conversion efficiency (PCE) of 3.11% due to an Eloss of 0.48 eV, which is smaller than the empirical limit of 0.6 eV. Based on the electrochemistry and theoretical calculations, we revealed that the efficient photovoltaic performance of the TT-2PPAB-based device can be ascribed to the sufficiently deep LUMO level of TT-2PPAB for charge transfer to PC71BM.
AB - A small photon energy loss (Eloss) is one of the requisites for achieving near-infrared (NIR) small-molecule organic solar cells (SM-OSCs). Herein, we present two novel pyrrolopyrrole aza-BODIPY (PPAB)-based panchromatic chromophores, TT-2PPAB and DFBT-2PPAB, with an acceptor-donor-acceptor configuration for photovoltaic studies. Among them, in combination with [6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) acceptor, TT-2PPAB exhibits a moderate power conversion efficiency (PCE) of 3.11% due to an Eloss of 0.48 eV, which is smaller than the empirical limit of 0.6 eV. Based on the electrochemistry and theoretical calculations, we revealed that the efficient photovoltaic performance of the TT-2PPAB-based device can be ascribed to the sufficiently deep LUMO level of TT-2PPAB for charge transfer to PC71BM.
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U2 - 10.1016/j.dyepig.2022.111020
DO - 10.1016/j.dyepig.2022.111020
M3 - Article
AN - SCOPUS:85144555470
SN - 0143-7208
VL - 210
JO - Dyes and Pigments
JF - Dyes and Pigments
M1 - 111020
ER -
