Article
Chemistry, Multidisciplinary
Deshuang Tu, Jianyu Zhang, Yunxiao Zhang, Herman H. Y. Sung, Lijie Liu, Ryan T. K. Kwok, Jacky W. Y. Lam, Ian D. Williams, Hong Yan, Ben Zhong Tang
Summary: This study investigates the dependence of material structures and properties on molecular motions at the molecule and aggregate levels by designing and synthesizing luminogens with aggregation-induced emission (AIE). Experimental and theoretical analysis show that the active intramolecular motions at the excited state affect the structural conformations and emission of the molecules at single-molecule level, while the restriction of intramolecular motions in the nano/macroaggregate state leads to less twisted conformations with bright emission. Intermolecular motions in the macrocrystals of certain luminogens can be activated through external perturbations, allowing the crystals to undergo reversible deformation and exhibit excellent elastic performance.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Lili Zhang, Dan Deng, Kun Lu, Zhixiang Wei
Summary: This review summarizes the strategies for effective morphology control in all-small-molecule organic solar cells, providing practical insights and guidance for material design and device optimization, and promoting further development in this field.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Shengxi Zhou, Dongdong Xia, Shijie Liang, Baiqiao Liu, Jing Wang, Chengyi Xiao, Zheng Tang, Weiwei Li
Summary: Organic solar cells (OSCs) are a promising green energy technology, but the efficiency of small-molecule organic solar cells (SMOSCs) lags behind that of polymer-based OSCs. This study introduces a new fused-ring small-molecule donor (SMD) design that significantly improves the efficiency of SMOSCs. The fused-ring design enhances the molecular planarity and charge transport, optimizing the microstructure and phase separation in the blends.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Yanling Chen, Sanyin Qu, Qingfeng Song, Wei Shi, Hui Li, Qin Yao, Lidong Chen
Summary: By introducing nanoscale phase separations and tailoring nanoscale interfaces, the thermoelectric performance of organic small molecules can be optimized, achieving synergistically optimized electrical and thermal transport properties.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Review
Materials Science, Multidisciplinary
Bin Kan, Yuanyuan Kan, Lijian Zuo, Xueliang Shi, Ke Gao
Summary: Recent breakthroughs have been made in solution-processed organic solar cells combining small-molecule donor and nonfullerene acceptor, with certified efficiency over 15%. By modifying materials and optimizing morphology, researchers have achieved impressive progress in this area. Small-molecule materials with easily tuned properties will be a key focus for future developments.
Article
Chemistry, Physical
L-N Wu, M-Y Li, M-Y Sui, J-C Huang, G-Y Sun, L. Cheng
Summary: This study aimed to compensate for the inherent defects of porphyrin small molecules in organic solar cells. By designing mono-porphyrin donor molecules with modified pi-bridges and combining them with non-fullerene acceptors, the absorption range was extended to the near-infrared region, leading to higher device efficiency.
MATERIALS TODAY ENERGY
(2021)
Article
Multidisciplinary Sciences
Huazhe Liang, Xingqi Bi, Hongbin Chen, Tengfei He, Yi Lin, Yunxin Zhang, Kangqiao Ma, Wanying Feng, Zaifei Ma, Guankui Long, Chenxi Li, Bin Kan, Hongtao Zhang, Oleg A. Rakitin, Xiangjian Wan, Zhaoyang Yao, Yongsheng Chen
Summary: Given the ease of synthesis and polarization of bromine compared to homomorphic fluorine and chlorine, it is surprising that high-performance brominated small molecule acceptors are rare. This may be due to undesirable film morphologies caused by steric hindrance and excessive crystallinity. To overcome this, three acceptors were constructed with stepwise bromination on central units to enhance intermolecular packing, crystallinity, and dielectric constant without damaging favorable intermolecular packing through end groups. As a result, PM6:CH22-based binary organic solar cells achieved the highest efficiency of 19.06% for brominated acceptors, and a record-breaking efficiency of 15.70% when the active layers were further thickened to around 500 nm. By exhibiting such a rare high-performance brominated acceptor, this work highlights the potential for achieving record-breaking organic solar cells through delicate bromination.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ziyun Huang, Ruimin Zhou, Min Lv, Hao Zhang, Chen Yang, Yanan Shi, Yi Tang, Jianqi Zhang, Kun Lu, Zhixiang Wei
Summary: This study introduces a new method to improve the performance of all-small-molecule organic solar systems through ternary strategies, incorporating a small amount of the IDIC acceptor into a ZR1-Cl : IDIC-4Cl based binary system. Results show that the good miscibility enabled by two structurally similar acceptors can enhance short circuit current, open circuit voltage, and fill factor, thereby increasing power conversion efficiency.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Jinhua Gao, Na Yu, Zhihao Chen, Yanan Wei, Congqi Li, Tianhua Liu, Xiaobin Gu, Jianqi Zhang, Zhixiang Wei, Zheng Tang, Xiaotao Hao, Fujun Zhang, Xin Zhang, Hui Huang
Summary: This study utilized a ternary donor alloy strategy to precisely tune the energy of charge transfer (CT) state in organic solar cells (OSCs), leading to improved efficiency. By adjusting the energy of CT state, energy loss was reduced, hybridization between localized excitation state and CT state was promoted, and optimal morphology was achieved, resulting in a significantly enhanced efficiency.
Review
Chemistry, Multidisciplinary
Huanhuan Gao, Yanna Sun, Lingxian Meng, Chenyang Han, Xiangjian Wan, Yongsheng Chen
Summary: This review summarizes recent progress in small-molecule donors and non-fullerene acceptors in organic solar cells, highlighting the structure-property relationships and morphology regulation strategies. Challenges and outlook for all-small-molecule organic solar cells are also discussed.
Article
Chemistry, Applied
Pengfei Li, Yi Wang, Zhiyong Chai, S. Shyam Shankar, Xu Liang, Haijun Xu, Ganesh D. Sharma
Summary: In this study, we synthesized and fabricated small molecule donors based on BODIPY dimer, named DI-BDP-CZ, for organic solar cells. The electrochemical research demonstrated that DI-BDP-CZ had energy levels well matched with both PC71BM and Y6. The optimized DI-BDPCZ: PC71BM and DI-BDP-CZ: Y6 based organic solar cells achieved overall power conversion efficiency of 7.63% and 12.58%, respectively.
Review
Chemistry, Multidisciplinary
Zhenghui Luo, Tongle Xu, Cai'e Zhang, Chuluo Yang
Summary: Thanks to their broad absorption spectra, easily modifiable molecular energy levels and chemical structures, nonfullerene small-molecule acceptors (SMAs) have attracted significant attention in the recent decade. To date, SMAs and polymer donor-based organic solar cells (OSCs) have achieved power conversion efficiencies (PCEs) of over 19%. Side-chain engineering has emerged as an effective method for enhancing the photovoltaic efficiency of nonfullerene SMAs, and this article summarizes the side-chain engineering of SMAs, providing insights into their structure-performance relationships and future optimization challenges.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Review
Chemistry, Multidisciplinary
Quan Liu, Koen Vandewal
Summary: Organic solar cells benefit from non-fullerene acceptors (NFA) due to their high absorption coefficients, tunable frontier energy levels, and optical gaps, as well as their relatively high luminescence quantum efficiencies as compared to fullerenes. This review summarizes the understanding and quantification of non-radiative decay, as well as strategies for suppressing these losses, in order to guide researchers in finding future solar harvesting donor-acceptor blends with high efficiency.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Kyra N. Schwarz, Valerie D. Mitchell, Saeed-Uz-Zaman Khan, Calvin Lee, Adam Reinhold, Trevor A. Smith, Kenneth P. Ghiggino, David J. Jones, Barry P. Rand, Gregory D. Scholes
Summary: The morphology of organic semiconductors plays a critical role in the function of optoelectronic devices, especially in donor-acceptor mixtures within organic solar cells. Energy landscapes are shown to drive charge accumulation away from interfaces, forming large electric fields, similar to a capacitor. Adjusting annealing conditions affects domain purity and electro-absorption, demonstrating the importance of energy landscapes in shaping charge movement and the necessity of pure domains for reduced recombination and large electric fields.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Energy & Fuels
Chao Hu, Jingjing Xu, Songming Cai, Peihao Huang, Jiyeon Oh, Changduk Yang, Shanshan Chen, Kuan Sun, Ke Yang, Shirong Lu
Summary: The research found that using fused-aromatic-ring as a conjugated side chain strategy can effectively improve the performance of organic solar cell devices by fine-tuning and enhancing molecular stacking/orientation and phase separation. This resulted in devices with increased short-circuit current density, higher fill factor, and improved power conversion efficiency.
Article
Materials Science, Multidisciplinary
Simon Schweidler, Henrik Schopmans, Patrick Reiser, Evgeniy Boltynjuk, Jhon Jairo Olaya, Surya Abhishek Singaraju, Franz Fischer, Horst Hahn, Pascal Friederich, Leonardo Velasco
Summary: High-entropy alloys offer a wide research area for new material compositions and applications. A high-throughput magnetron sputtering synthesis method is presented to fabricate a new HEA gradient layer, allowing for the study of the composition of the HEA system and the influence of individual elements on material properties.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Physical
Konrad Wojtaszek, Filip Cebula, Bogdan Rutkowski, Magdalena Wytrwal, Edit Csapo, Marek Wojnicki
Summary: This study synthesized core-shell nanoparticles with a Ni core and a Ag-Ni nano alloy shell by reducing Ni and Ag ions with sodium borohydride in the presence of trisodium citrate as a stabilizer. XRD and XPS spectroscopic studies were conducted to determine the phase composition and oxidation states of the nanoparticles, respectively. The composition and shape of the particles were determined using HR-TEM EDS testing. The obtained nanoparticles had a size of 11 nm. Catalytic activity research was carried out using a methylene blue reduction system, and the catalytic activity of the colloids was measured using UV-Vis spectrophotometry. The Ag-Ni alloy exhibited approximately ten times higher catalytic activity than pure silver nanoparticles of a similar size.
Article
Chemistry, Multidisciplinary
Sigurd Mertens, Bernhard Siegmund, Koen Vandewal
Summary: This study combines spectroscopic measurements with photothermal techniques to accurately determine the photoluminescence quantum yield (PLQY) of six fluorescent molecules in low concentration solutions. The measurement method demonstrates high reliability and can detect phonon-assisted optical upconversion when the photon energy is below the photothermal threshold. It is found that perylene red solution has the highest PLQY, while the presence of low energy sub-gap impurities in perylene orange solution prevents upconversion.
MATERIALS HORIZONS
(2023)
Article
Nanoscience & Nanotechnology
Pascal Kaienburg, Helen Bristow, Anna Jungbluth, Irfan Habib, Iain McCulloch, David Beljonne, Moritz Riede
Summary: The advent of nonfullerene acceptors (NFAs) has achieved over 19% power conversion efficiency in laboratory organic photovoltaics (OPVs). However, high-efficiency NFAs have only been realized in solution-processed blends. Vacuum thermal evaporation (VTE) is crucial for real-world OPV commercialization due to its successful track record in upscaled industrial production. In this study, we demonstrate that using VTE donors with NFAs instead of the current standard acceptor C-60 can significantly reduce voltage losses, highlighting the immense potential of evaporable NFAs and the urgent need for smaller, evaporable compounds.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Marti Gibert-Roca, Miquel Casademont-Vinas, Quan Liu, Koen Vandewal, Alejandro R. Goni, Mariano Campoy-Quiles
Summary: This work proposes a novel spectral splitting device concept called RAINBOW, which lays various semiconducting junctions with cascading bandgaps side by side to improve the efficiency of organic solar cells. Simulations and experiments show that this geometry can reduce thermalization losses and improve light harvesting, resulting in a 46.6% relative improvement in efficiency compared to the best sub-cell. A working proof-of-concept monolithic device consisting of two sub-cells deposited from solution on the same substrate is successfully fabricated, demonstrating the feasibility and potential of the RAINBOW solar cell concept.
ADVANCED MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Quan Liu, Koen Vandewal
Summary: Organic solar cells benefit from non-fullerene acceptors (NFA) due to their high absorption coefficients, tunable frontier energy levels, and optical gaps, as well as their relatively high luminescence quantum efficiencies as compared to fullerenes. This review summarizes the understanding and quantification of non-radiative decay, as well as strategies for suppressing these losses, in order to guide researchers in finding future solar harvesting donor-acceptor blends with high efficiency.
ADVANCED MATERIALS
(2023)
Article
Engineering, Civil
Lukasz Rakoczy, Malgorzata Grudzien-Rakoczy, Bogdan Rutkowski, Rafal Cygan, Fabian Hanning, Grzegorz Cios, Stefan Habisch, Joel Andersson, Peter Mayr, Anna Zielinska-Lipiec
Summary: This study investigates the influence of microstructural constituents on liquation crack formation in the cast Ni-based superalloy, Rene 108. It is found that the base material has a complex microstructure, including gamma matrix, gamma' precipitates, MC and M23C6 carbides, and M5B3 borides. The constitutional liquation in the alloy leads to a significant reduction in strength and ductility, resulting in low weldability. In the heat-affected zone, mainly gamma' precipitates undergo constitutional liquation, forming a thin non-equilibrium liquid film along high-angle grain boundaries, which initiates and propagates cracks during cooling.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Optics
Oskar J. Sandberg, Christina Kaiser, Stefan Zeiske, Nasim Zarrabi, Sam Gielen, Wouter Maes, Koen Vandewal, Paul Meredith, Ardalan Armin
Summary: Researchers demonstrate that the dark saturation current in organic photodiodes is fundamentally limited by mid-gap trap states, which leads to an upper limit for specific detectivity. Photodiodes are widely used in industry and consumer electronics. The use of organic semiconductors has gained considerable interest due to their versatile optoelectronic properties and potential for low-cost manufacturing.
Article
Chemistry, Physical
Rachith Shanivarasanthe Nithyananda Kumar, Robbe Breugelmans, Xueshi Jiang, Shabnam Ahadzadeh, Guy Brammertz, Pieter Verding, Michael Daenen, Melissa Van Landeghem, Sofie Cambre, Koen Vandewal, Wim Deferme
Summary: The use of polyethylenimine ethoxylated (PEIE), Zinc oxide (ZnO) nanoparticles, and a PEIE-ZnO nanocomposite as functional layers for OLEDs fabricated by solution processing improves electron injection and hole blocking properties, resulting in increased external quantum efficiency. This novel deposition technique offers comparable OLED performance to spin coated and vacuum deposited electron injection layers, enabling the large area fabrication of optoelectronic devices with high efficiencies, high output, low cost, and long lifetime.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Sander Smeets, Quan Liu, Jochen Vanderspikken, Tyler James Quill, Sam Gielen, Laurence Lutsen, Koen Vandewal, Wouter Maes
Summary: Traditional synthesis methods and catalysts have limitations for the commercial application of organic solar cells. By using flow chemistry and defect-free synthesis, we have successfully synthesized high-efficiency organic photovoltaic materials with tailorable molar mass.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Pierfrancesco Maltoni, Gianni Barucca, Bogdan Rutkowski, Maria Chiara Spadaro, Petra E. Jonsson, Gaspare Varvaro, Nader Yaacoub, Jose A. De Toro, Davide Peddis, Roland Mathieu
Summary: The magnetic coupling of SrFe12O19/CoFe2O4 nanocomposites is investigated. The structural coherence and texture at the interfaces of the nanostructures are evidenced by advanced electron microscopy. The exchange intergranular interaction is evidenced and the critical thickness for uniform reversal of coupled interfaces is quantified.
Review
Nanoscience & Nanotechnology
Dorothea Scheunemann, Clemens Goehler, Constantin Tormann, Koen Vandewal, Martijn Kemerink
Summary: With power conversion efficiencies approaching 20%, organic solar cells have gained recognition in the field of photovoltaics. However, there is still a need for further improvement in energy and current management. The interpretation schemes for associated losses of energy and charge vary, hindering the design of next-generation organic solar cells. This article reviews important concepts, addresses open questions, and highlights implications for device performance and improvement.
ADVANCED ELECTRONIC MATERIALS
(2023)
Editorial Material
Nanoscience & Nanotechnology
L. Schmidt-Mende, S. Kraner, M. White, K. Vandewal
Article
Nanoscience & Nanotechnology
Irfan Habib, Pascal Kaienburg, Dondong Xia, Olivia Gough, Ming Zhu, Joseph Spruce, Weiwei Li, Moritz Riede
Summary: Since non-fullerene acceptors (NFAs) replaced fullerene derivatives, the power conversion efficiency of solution-processed organic solar cells (OSCs) has almost doubled. However, the successful transition from C-60 to NFAs is still pending for vacuum-thermal evaporated (VTE) OSCs due to the size limitation of NFAs. Discovering high-performing VTE NFAs is crucial for industrial manufacturing.
Article
Chemistry, Physical
S. Paredis, T. Cardeynaels, S. Brebels, J. Deckers, S. Kuila, A. Lathouwers, M. Van Landeghem, K. Vandewal, A. Danos, A. P. Monkman, B. Champagne, W. Maes
Summary: Three novel TADF emitters based on Qx-Ph-DMAC fluorophore are designed and synthesized, showing improved TADF performance through stepwise modifications including the addition of an extra phenyl ring, incorporation of an electron-deficient coumarin unit, and 'locking' the molecular structure.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
