A high dielectric constant non-fullerene acceptor for efficient bulk-heterojunction organic solar cells

Liu, Xi; Xie, Boming; Duan, Chunhui; Wang, Zhaojing; Fan, Baobing; Zhang, Kai; Lin, Baojun; Colberts, Fjm Fallon; Ma, Wei; Janssen, Raj René; Huang, Fei; Cao, Yong

doi:10.1039/c7ta10136h

Cited by 323 publications

(221 citation statements)

References 47 publications

Supporting

Mentioning

205

Contrasting

Unclassified

Order By: Relevance

“…2019, 9,1901740 FWHM represents full-width at half maximum; b) CCL represents crystal coherence length. [28,29] These results are shown in Figure S10 and Table S7 in the Supporting Information. Energy Mater.…”

Section: Solubility and Interaction Parametersmentioning

confidence: 68%

Alkyl Chain Length Effects of Polymer Donors on the Morphology and Device Performance of Polymer Solar Cells with Different Acceptors

Pang

Zhang

Duan

et al. 2019

Advanced Energy Materials

Self Cite

View full text Add to dashboard Cite

The development of nonfullerene acceptors has brought polymer solar cells into a new era. Maximizing the performance of nonfullerene solar cells needs appropriate polymer donors that match with the acceptors in both electrical and morphological properties. So far, the design rationales for polymer donors are mainly borrowed from fullerene‐based solar cells, which are not necessarily applicable to nonfullerene solar cells. In this work, the influence of side chain length of polymer donors based on a set of random terpolymers PTAZ‐TPD10‐Cn on the device performance of polymer solar cells is investigated with three different acceptor materials, i.e., a fullerene acceptor [70]PCBM, a polymer acceptor N2200, and a fused‐ring molecular acceptor ITIC. Shortening the side chains of polymer donors improves the device performance of [70]PCBM‐based devices, but deteriorates the N2200‐ and ITIC‐based devices. Morphology studies unveil that the miscibility between donor and acceptor in blend films depends on the side chain length of polymer donors. Upon shortening the side chains of the polymer donors, the miscibility between the donor and acceptor increases for the [70]PCBM‐based blends, but decreases for the N2200‐ and ITIC‐based blends. These findings provide new guidelines for the development of polymer donors to match with emerging nonfullerene acceptors.

show abstract

Section: Solubility and Interaction Parametersmentioning

confidence: 68%

Alkyl Chain Length Effects of Polymer Donors on the Morphology and Device Performance of Polymer Solar Cells with Different Acceptors

Pang

Zhang

Duan

et al. 2019

Advanced Energy Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…This might originate from the strong intramolecular dipole and increased polarizability of IT4F molecules . In addition, the highest ε r for PBDB‐T‐2Cl:IT4F blend could be ascribed to the more ordered molecular packing of both the chlorine‐containing donor and fluorine‐containing acceptor, supporting the easier reorientations for molecular dipole moments in BHJ films …”

Section: Resultsmentioning

confidence: 87%

Multiple Temporal‐Scale Photocarrier Dynamics Induced by Synergistic Effects of Fluorination and Chlorination in Highly Efficient Nonfullerene Organic Solar Cells

et al. 2020

View full text Add to dashboard Cite

Fluorination and chlorination have yielded a novel class of materials and achieved tremendous progress in enhancing photovoltaic efficiency in organic solar cells (OSCs). However, their effects on photocarrier dynamics remain elusive in these organic photovoltaic systems. Herein, a comprehensive study on the underlying mechanisms is conducted based on a 2 × 2 photovoltaic matrix, consisting of PBDB‐T, PBDB‐T‐2Cl, ITIC, and IT4F. Chlorination of donors enhances exciton migration and relaxation rates and promotes the extraction of polarons. The more efficient charge transfer and a larger proportion of long‐lived polarons are observed in fluorine‐containing acceptor‐based systems, which are in favor of charge generation in the actual devices. According to the enlarged dielectric constant in the PBDB‐T‐2Cl:IT4F blend, the improved exciton delocalization, the decreased exciton binding energy, and Coulomb capture radius are obtained relative to other three binary systems, which can increase charge separation efficiency and reduce the probability of bimolecular recombination. The simultaneous fluorination and chlorination can optimize molecular packing and nanoscale phase separation, facilitating effective exciton diffusion, exciton dissociation, and charge transport. These results highlight the important role of fluorination and chlorination on these fundamental mechanisms, possibly resulting in some new molecular design principles toward high‐performance OSCs.

show abstract

“…[35] The kinetic Monte Carlo (kMC) method is a powerful simulation technique to model the time-dependent behavior of physical systems. [11,12,[51][52][53][54][55][56][57][58][59][60] In addition, pristine organic materials with low energetic disorder support separation dynamics: a low disorder leads to a more ballistic transport and more efficient separation. [36] A specific advantage of the kMC method is that it allows to include explicit particle-particle interactions and that it gives direct access to the charge trajectories which can be used to assess the CP displacement from the heterojunction.…”

Section: Wwwadvtheorysimulcommentioning

confidence: 99%

Charge Pair Separation Dynamics in Organic Bulk‐Heterojunction Solar Cells

Albes

Gagliardi

2018

Advcd Theory and Sims

View full text Add to dashboard Cite

Charge pair separation in organic bulk-heterojunction (BHJ) solar cells is a complex interplay between numerous factors, such as the spatial geometry of the blend, the distribution of energetic disorder, the electric field, thermal fluctuations, and the mutual electron-hole Coulomb attraction. Insufficient separation from the interface and concomitant charge pair recombination is a main limitation in improving the PCE of organic BHJ solar cells and requires an in-depth understanding of the timescales involved. Here, a 3D kinetic Monte Carlo model of a BHJ organic solar cell is set up and the time-dependent evolution of mutual electron-hole pair distances separating from the heterojunction interface is investigated. Large fluctuations in separation times are found, in particular in dependence of the energetic disorder and the permittivity of the organic materials. At commonly observed values of energetic disorder, slight modifications of the permittivity can drastically influence the charge separation time and even outweigh orders of magnitude of geminate recombination rates, hence help to suppress geminate recombination. Thus, the results strongly support the recent trend of developing high-permittivity organic materials for solar cell applications.

show abstract

A high dielectric constant non-fullerene acceptor for efficient bulk-heterojunction organic solar cells

Cited by 323 publications

References 47 publications

Alkyl Chain Length Effects of Polymer Donors on the Morphology and Device Performance of Polymer Solar Cells with Different Acceptors

Alkyl Chain Length Effects of Polymer Donors on the Morphology and Device Performance of Polymer Solar Cells with Different Acceptors

Multiple Temporal‐Scale Photocarrier Dynamics Induced by Synergistic Effects of Fluorination and Chlorination in Highly Efficient Nonfullerene Organic Solar Cells

Charge Pair Separation Dynamics in Organic Bulk‐Heterojunction Solar Cells

Contact Info

Product

Resources

About