Two low-bandgap (LGB) conjugated polymers ( P1 and P2) based on thiophene-phenylene-thiophene (TPT) with adequate energy levels have been designed and synthesized for application in bulk-heterojunction polymer solar cells (PSCs). The absorption spectral, electrochemical, field effect hole mobility and photovoltaic properties of LGB TPT derivatives are investigated and compared with poly(3-hexylthiophene) (P3HT). Photophysical studies reveal bandgaps of 1.76 eV for P1 and 1.70 eV for P2, which could effectively harvest broader solar spectrum. In addition, the thin film absorption coefficients of P1 and P2 are 1.6 x 10 (5) cm (-1) (lambda approximately 520 nm) and 1.4 x 10 (5) cm (-1) (lambda approximately 590 nm), respectively. Electrochemical studies indicate desirable HOMO/LUMO levels that enable a high open circuit voltage while blending them with fullerene derivatives as electron acceptors. Furthermore, both materials show sufficient hole mobility (3.4 x 10 (-3) cm (2)/Vs for P2) allowing efficient charge extraction and a good fill-factor for PSC application. High-performance power conversion efficiency (PCE) of 4.4% is obtained under simulated solar light AM 1.5 G (100 mW/cm (2)) from PSC device with an active layer containing 25 wt% P2 and 75 wt% [6,6]-phenyl-C71-butyric acid methyl ester (PC 71BM), which is superior to that of the analogous P3HT cell (3.9%) under the same experimental condition.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja801877k | DOI Listing |
Polymers (Basel)
January 2025
School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China.
In organic solar cells, the aggregation and crystallization of polymers are significant for bulk heterojunction. Blending with acceptor materials, polymer donor materials can adjust their aggregation by the movement of the chain segments. In this paper, the unfused structures based on thiophene and carbazole are respectively designed and introduced into the donor-acceptor copolymer donor materials to investigate the influence of flexible and rigid structures on polymer-aggregation leading photoelectric performance.
View Article and Find Full Text PDFNat Mater
January 2025
Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, China.
Printing of large-area solar panels necessitates advanced organic solar cells with thick active layers. However, increasing the active layer thickness typically leads to a marked drop in the power conversion efficiency. Here we developed an organic semiconductor regulator, called AT-β2O, to tune the crystallization sequence of the components in active layers.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Conjugated polymer donors have always been one of the important components of organic solar cells (OSCs), particularly those featuring simple synthetic routes, proper energy levels, and appropriate aggregation behavior. In this work, we employed a nonfused electron-deficient building block, dicyanobithiophene (2CT), for constructing high-performance donors. Combining this with side-chain engineering, two novel halogen-free polymer donors, PB2CT-BO and PB2CT-HD, were reported.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Voevodsky Institute of Chemical Kinetics and Combustion of Siberian Branch of Russian Academy of Sciences, Institutskaya 3, 630090 Novosibirsk, Russia.
We developed a technique allowing the direct observation of photoinduced charge-transfer states (CTSs)-the weakly coupled electron-hole pairs preceding the completely separated charges in organic photovoltaic (OPV) blends. Quadrature detection of the electron spin echo (ESE) signal enables the observation of an out-of-phase ESE signal of CTS. The out-of-phase Electron-Electron Double Resonance (ELDOR) allows measuring electron-hole distance distributions within CTS and its temporal evolution in the microsecond range.
View Article and Find Full Text PDFAdv Mater
December 2024
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids and State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Highly efficient nonfullerene acceptors (NFAs) for organic solar cells (OSCs) with low energy loss (E) and favorable morphology are critical for breaking the efficiency bottleneck and achieving commercial applications of OSCs. In this work, quinoxaline-based NFAs are designed and synthesized using a synergistic isomerization and bromination approach. The π-expanded quinoxaline-fused core exhibits different bromination sites for isomeric NFAs, namely AQx-21 and AQx-22.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!