A subscription to JoVE is required to view this content. Sign in or start your free trial.
Indacenodithienothiophene-Based Ternary Organic Solar Cells: Concept, Devices and Optoelectronic Analysis
Not Published
In This Article
Summary
In this study, in addition to the synthesis of a novel polymer, we fully characterize a ternary bulk-heterojunction solar cell, with a power conversion efficiency exceeding 4.6%, with the complementary use of optical and electrical techniques.
Abstract
We report on a novel ternary bulk-heterojunction solar cell by implementing a novel conjugated polymer (ADV-2) containing alternating pyridyl[2,1,3]thiadiazole (PT) between two different donor fragments, dithienosilole (DTS) and indacenodithienothiophene (IDTT), into a host system of indacenodithieno[3,2-b]thiophene,2,3-bis(3-(octyloxy)phenyl)quinoxaline (PIDTTQ) and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM). A clear absorption contribution in the near infrared (NIR) region leads to a power conversion efficiency (PCE) exceeding 4.6% in ternary device processed by doctor blading in air, fully avoiding any thermal treatment. Current-voltage (J-V) characteristics, external quantum efficiency (EQE) spectrum, charge extraction (CE) as well as photo-induced absorption (PIA) spectroscopy reveal the higher charge carrier generation in the ternary devices compared to the reference binary cells. Despite an enhancement of about 20% in the short circuit current density (Jsc), the lower fill factor (FF) achieved in PIDTTQ:ADV-2:PC71BM ternary system limits the solar cell performance. With the complementary use of photoinduced charge carrier extraction by linearly increasing voltage (photo-CELIV) and transient photovoltage (TPV) measurements, we found that the ternary cells suffer from a lower mobility-lifetime (µτ) product, adversely impacting the FF. However, the significant improvement of light harvesting in the NIR region, compensating the transport losses, results in an overall power conversion efficiency enhancement of ~7% for ternary blends as compared to the PIDTTQ: PC71BM devices.
Introduction
During the last decades, the power conversion efficiency (PCE) of organic bulk-hetorojunction (BHJ) solar cells based on donor/acceptor blends surpassed the 10% threshold, mainly due to the discovery of novel materials as well as device structure engineering.1,2,3,4,5,6 Nowadays, one of the main challenges in order to further boost the PCE of organic solar cells is to achieve better absorption match to the solar irradiance spectrum, by extending the narrow absorption windo....
Protocol
1. Planning of experiment
- Identify two donor copolymers with complementary absorption in the visible-NIR range and with suitable energy levels in comparison with the fullerene derivative acceptor (PC71BM).
2. Synthesis of M1
- Add a 10 mL freshly distilled toluene solution containing 5,5'-bis(trimethylstannyl)-3,3'-di-2-ethylhexylsilylene-2,2'-bithiophene (0.372 g, 0.5 mmol, the quantity as well as the representative mmol corresponds to 5,5&#.......
Representative Results
Figure 1 shows 1H and 13C NMR spectra of M1 (a-b, respectively) and ADV-2 (c-d, respectively) with their respectively list of peaks. Figure 2 shows the synthetic route for the low band gap donor-acceptor copolymer ADV-2. Figure 3 shows the absorption spectrum of ADV-2 in DCB solution and as solid. The copolymer for both cases shows a single band in the high energy region which is assigned to a localized π−π* transition and another a.......
Discussion
We reported a novel ternary system with a clear contribution in the incident photon-to-current efficiency in the near IR region. A Jsc improvement of around 20% was obtained for PIDTTQ:ADV-2:PC71BM (0.85:0.15:2) ternary devices compared to PIDTTQ:PC71BM binary cells. However, the low FF limited the performances of the ternary BHJ solar cells.
We found that by adding ADV-2 into the host system of PIDTTQ:PC71BM the μ`.......
Acknowledgements
This project has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under the Grant Agreement n° 607585 project OSNIRO. In addition, this project has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under the Grant Agreement no. 331389. C. L. C. acknowledges the financial support of a Marie Curie Intra European Fellowship (FP7-PEOPLE-2012-IEF) project ECOCHEM. G. P. would like to thank the Ministry of Education and Religious Affairs in Greece for the financial support of this work provided under the co-operational program "AdvePol: E850". The authors gratefully acknowledge the suppo....
Materials
| Name | Company | Catalog Number | Comments |
| 1,2-Dichlorobenzene | Aldrich | 606078 | solvent |
| 1-Chloronaphtalene | Aldrich | 970836 | solvent |
| chloroform | Aldrich | 1731042 | solvent |
| PC71BM | Solenne | 07099 | BHJ material |
| Toluene | Aldrich | 2036259 | solvent |
| Chloroform-d | Aldrich | 1697633 | solvent |
| trichlorobenzene | Aldrich | 956819 | solvent |
| 5,5’-bis(trimethylstannyl)-3,3’-di-2-ethylhexylsilylene-2,2’-bithiophene | Aldrich | 143367-56-0 | starting material |
| Pd(PPh3)4 | Aldrich | 14221-01-3 | catalyst |
| source measurements unit | BoTEst | ||
| Solar simulator Oriel Sol 1A | Newport | ||
| Spectrometer Lambda 950 | Perkin Elmer | ||
| EQE setup | Enlitech | ||
| oscilloscope DSO-X 2024A | Agilent Technologies | ||
| NMR setup | Bruker AVANCE III 600 | ||
| GPC setup | Alliance 2000 | ||
| Doctor blade | Zehntner ZAA 2300 | ||
| evaporator | mbraun | ||
| glove boxes | mbraun | ||
| Laser 405 nm | THORLABS | ||
| funtion generator | Agilent Technologies 33500B series |
References
- Brabec, C. J., Sariciftci, N. S., Hummelen, J. C. Plastic Solar Cells. Adv. Funct. Mater. 11 (1), 15-26 (2001).
- Vohra, V., et al. Efficient inverted polymer solar cells employing favourable molecular orientation. Nat....
This article has been published
Video Coming Soon
ABOUT JoVE
Copyright © 2024 MyJoVE Corporation. All rights reserved