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Polymerization of Y6-type acceptor molecules leads to bulk-heterojunction organic solar cells with both high power-conversion efficiency and device stability, but the underlying mechanism remains unclear. Here we show that the exciton recombination dynamics of polymerized Y6-type acceptors (Y6-PAs) strongly depends on the degree of aggregation. While the fast exciton recombination rate in aggregated Y6-PA competes with electron-hole separation at the donor-acceptor (D-A) interface, the much-suppressed exciton recombination rate in dispersed Y6-PA is sufficient to allow efficient free charge generation. Indeed, our experimental results and theoretical simulations reveal that Y6-PAs have larger miscibility with the donor polymer than Y6-type small molecular acceptors, leading to D-A percolation that effectively prevents the formation of Y6-PA aggregates at the interface. Besides enabling high charge generation efficiency, the interfacial D-A percolation also improves the thermodynamic stability of the blend morphology, as evident by the reduced device "burn-in" loss upon solar illumination.
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http://dx.doi.org/10.1038/s41467-024-45455-0 | DOI Listing |
J Phys Chem Lett
September 2025
School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
Inverted quantum dot light-emitting diodes (QLEDs) show great promise for next-generation displays due to their compatibility with integrated circuit architectures. However, their development has been hindered by inefficient exciton utilization and charge transport imbalance. Here, we present a strategy for regulating charge-exciton dynamics through the rational design of a multifunctional hole transport layer (HTL), incorporating polyethylenimine ethoxylated (PEIE) as a protective interlayer in fully-solution-processed inverted red QLEDs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Organic Electronic Materials Laboratory, Department of Information Display, College of Sciences, Kyung Hee University, Seoul 02447, Republic of Korea.
Solution-processed phosphorescent inverted organic light-emitting diodes (s-IOLEDs) have garnered significant attention due to their excellent stability and high performance. However, frequently used inorganic electron transport layers usually cause exciton dissociation at the emitting layer interface, leading to low device efficiency and severe efficiency roll-off. In this work, we designed a cross-linkable triazine-grafted electron transport copolymer (PPDPT--PBCB) with a high triplet energy (3.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-Ku, Yokohama 236-0027, Kanagawa, Japan.
Perovskite-silicon tandem solar cells have attracted considerable attention owing to their high power conversion efficiency (PCE), which exceeds the limits of single-junction devices. This study focused on lead-free tin-based perovskites with iodine-bromine mixed anions. Bromide perovskites have a wide bandgap; therefore, they are promising light absorbers for perovskite-silicon tandem solar cells.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
For optoelectronic devices based on lead-halide perovskites and other semiconductors, a comprehensive understanding of the electric field influences on the carrier transport characteristics is critical to the optimization of their practical performances. To fulfill this challenging goal, here we have employed photoluminescence spatial image and transient absorption microscopy measurements on an individual CsPbBr microplate biased at external voltages in an Au/CsPbBr/Au device. At the subpicosecond time scale, some photogenerated excitons are dissociated into free electrons and holes that drift toward the electrodes to leave behind unfilled defect sites, which are capable of scattering the residual excitons to yield a reduced diffusion coefficient.
View Article and Find Full Text PDFJ Phys Chem Lett
September 2025
School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute Jatni, Khurda, Bhubaneswar 752050, Odisha, India.
Quantum-confined perovskites represent an emerging class of materials with great potential for optoelectronic applications. Specifically, zero-dimensional (0D) perovskites have garnered significant attention for their unique excitonic properties. However, achieving phase-pure, size-tunable 0D perovskite materials and gaining a clear understanding of their photophysical behavior remains challenging.
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