Review
Chemistry, Physical
Dan Zhou, Jianru Wang, Zhentian Xu, Haitao Xu, Jianwei Quan, Jiawei Deng, Yubing Li, Yongfen Tong, Bin Hu, Lie Chen
Summary: Organic solar cells (OSCs) have made significant progress in recent years due to their low cost, lightweight, mechanical flexibility, and printable fabrication. The nonfullerene acceptors (NFAs) play an important role in widening the absorption range, enhancing stability, and increasing the power conversion efficiency (PCE) of OSCs. As a result, NFAs have attracted increasing attention for their inherent advantages. Currently, the PCE of OSCs has been elevated to over 20%. Small molecule and polymer NFAs are crucial in OSCs.
Article
Energy & Fuels
Wei Gao, Francis R. Lin, Alex K-Y Jen
Summary: This article focuses on the development of near-infrared nonfullerene acceptors (NFAs) in organic solar cells (OSCs), discussing their molecular design strategies, structure-property-performance relationships, and the potential in fabricating ternary and tandem OSCs. Outlooks for future design of NIR NFAs are also provided, considering material stability and production cost based on current knowledge, in hope of aiding the further development of the field.
Article
Chemistry, Multidisciplinary
Hai-Rui Bai, Qiaoshi An, Mengyun Jiang, Hwa Sook Ryu, Jie Yang, Xue-Jiao Zhou, Hong-Fu Zhi, Can Yang, Xiong Li, Han Young Woo, Jin-Liang Wang
Summary: By incorporating an asymmetric acceptor into binary blends, ternary organic solar cells (OSCs) were prepared. The good compatibility of two isogenous acceptors with similar chemical skeletons optimized the morphology and improved the photon absorption ability and energy level matching. The optimized ternary OSCs achieved high conversion efficiency and champion efficiency.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Joel Troughton, Sebastian Neubert, Nicola Gasparini, Diego Rosas Villalva, Jules Bertrandie, Akmaral Seitkhan, Sri Harish Kumar Paleti, Anirudh Sharma, Michele De Bastiani, Erkan Aydin, Thomas D. Anthopoulos, Stefaan De Wolf, Rutger Schlatmann, Derya Baran
Summary: Monolithically stacked tandem solar cells offer the opportunity to absorb more solar radiation with reduced energy loss, with carefully adjusted bandgaps to avoid competition for photons. Two-terminal tandem solar cells using wide bandgap amorphous silicon and narrow bandgap NFA bulk-heterojunction show high power conversion efficiencies exceeding 15%, with interface engineering allowing for stability across a wide range of light intensities. The addition of an inorganic silicon subcell enhances operational stability and reduces light-stress on the bulk heterojunction, addressing a longstanding challenge in organic photovoltaic research.
ADVANCED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Jinqiu Xu, Francis Lin, Lei Zhu, Ming Zhang, Tianyu Hao, Guanqing Zhou, Ke Gao, Yecheng Zou, Gang Wei, Yuanping Yi, Alex K. Y. Jen, Yongming Zhang, Feng Liu
Summary: This research investigates the structure features and intermolecular interactions of nonfullerene acceptors (NFAs) in single crystal and thin films, as well as their solar cell applications. Key parameters and intermolecular forces that lead to different crystalline packing motifs are identified. Atomic modification induces hydrogen bonding or pi-pi stacking column, resulting in different crystalline packing. Molecular assembly in thin films is initiated by hydrogen bonding and completed by pi-pi stacking reorganization. The crystalline packing motif is not directly related to device efficiency, but the crystalline morphology influences exciton/carrier dynamics and device performance. A broader understanding of the scaling behavior of organic semiconductor crystals ranging from oligoacenes to NFAs is established.
ADVANCED ENERGY MATERIALS
(2022)
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)
Article
Energy & Fuels
Mathias Nyman, Oskar J. Sandberg, Wei Li, Stefan Zeiske, Robin Kerremans, Paul Meredith, Ardalan Armin
Summary: To produce organic bulk-heterojunction solar cells with thick active layers and high efficiencies based on nonfullerene acceptors, it is important to consider factors such as charge carrier mobility, unintentional doping concentrations, and bimolecular recombination prefactor.
Article
Energy & Fuels
Baoda Xue, Gaosheng Huang, Boxin Wang, Hui Wang, Xinghua Shi, Bing Han, Hong Zhang, Yuan Zhang, Huiqiong Zhou
Summary: The study shows that the ending groups of non-fullerene acceptors play a significant role in interfacial modification in perovskite solar cells. By comparing different acceptors with various ending groups, it was found that the sulfur atom in the ITCC ending group enhances adsorption to the perovskite surface, leading to tighter contact and better charge transfer, ultimately improving device performance.
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
Junying Wu, Yanjun Liu, Hui-Chao Hu, Junjie Wen, Xuefeng Zhu, Xinhua Ouyang
Summary: With the rapid development of power conversion efficiency in nonfullerene acceptor organic solar cells, there is a new demand for interfacial modification due to the conformational anisotropy of NFAs. Noncovalent interactions between NFAs and an electron transport layer were found to enhance electron transport, leading to improved device performance.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Review
Energy & Fuels
Edigar Muchuweni, Bice S. Martincigh, Vincent O. Nyamori
Summary: Carbon-based materials such as graphene have unique optoelectronic properties that make them appealing for use in organic solar cells, potentially replacing the commonly used indium tin oxide anodes. Recent advancements have increased power conversion efficiency from around 0.63% to over 16.00%, with potential to approach the efficiency of silicon-based solar cells.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Yixu Tang, Hexiang Feng, Yuanying Liang, Haoran Tang, Zurong Du, Jiaxin Xu, Fei Huang, Yong Cao
Summary: The advances of small-molecular acceptors (SMAs) have recently inspired the development of high-performance organic solar cells (OSCs). SMAs with an A-D-C-D-A framework have gained attention for their tunable chemical structures and commercial synthesis capabilities. In this study, three SMAs with varying terminal groups, namely DTBCIC-Cl, DTBCIC-F, and DTBCIC-H, were synthesized using dithienobenzothiadiazol (DTBT) as the center unit. The terminal groups were found to affect the optical absorbance, energy levels, and molecular packing of the SMAs. Compared to DTBCIC-H, DTBCIC-Cl and DTBCIC-F exhibited red-shift absorption, well-matched energy levels with the polymer donor PM6, and closer molecular packing, resulting in wide absorption and improved morphology in blend films based on PM6:DTBCIC-Cl and PM6:DTBCIC-F. OSCs based on DTBCIC-Cl achieved a high power conversion efficiency of 12.71%. These results demonstrate that optimizing SMAs through altering terminal groups is a promising design strategy for achieving high-performance A-D-C-D-A SMAs.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Chemistry, Physical
Yunlong Ma, Ming Zhang, Shuo Wan, Pan Yin, Pengsong Wang, Dongdong Cai, Feng Liu, Qingdong Zheng
Summary: Controlling the molecular orientation of nonfullerene acceptors by adjusting side chains leads to improved device performance, with M3 showing higher efficiency compared to M32 when blended with a donor polymer such as PM6.
Article
Materials Science, Multidisciplinary
Yixu Tang, Hexiang Feng, Yuanying Liang, Haoran Tang, Zurong Du, Jiaxin Xu, Fei Huang, Yong Cao
Summary: The advances of small-molecular acceptors (SMAs) have driven the development of high-performance organic solar cells (OSCs) recently. SMAs with A-D-C-D-A framework have gained significant attention due to their easy tunability and commercial synthesis. In this study, dithienobenzothiadiazol (DTBT) was used as the central unit, and three different SMAs (DTBCIC-Cl, DTBCIC-F, and DTBCIC-H) were synthesized by changing the terminal groups. The optimization of terminal groups led to improved optical absorbance, energy levels, and molecular packing. OSCs based on DTBCIC-Cl achieved a high power conversion efficiency of 12.71%, demonstrating the promising design strategy of altering terminal groups for high-performance A-D-C-D-A SMAs.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Polymer Science
Zhengwei Hu, Juxuan Xie, Jiangkai Yu, Yi Zhang, Houji Cai, Yuanqing Bai, Kai Zhang, Chunchen Liu, Fei Huang, Yong Cao
Summary: This study introduces a novel six-membered fused electron-donating core containing B-N covalent bonds for constructing high-efficiency nonfullerene electron acceptors (NFEAs) in organic solar cells (OSCs). By modulating alkyl chains on the molecules, improved molecular packing and morphology are achieved, leading to enhanced power conversion efficiency (PCE) in OSCs.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Jisu Park, Chulyeon Lee, Taehoon Kim, Hwajeong Kim, Youngkyoo Kim
Summary: This study detailed a novel near-infrared-absorbing conjugated polymer from compound structure to optoelectronic properties, demonstrating its potential application in NIR sensing devices and investigating the changes in its photoelectric performance at different thicknesses.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Chulyeon Lee, Hwajeong Kim, Youngkyoo Kim
Summary: In this study, a novel polymer, PolyTPD, doped with BCF was found to exhibit broad optical absorption peaks in the short-wave infrared range with varying BCF molar ratios. The doping of PolyTPD with BCF resulted in the generation of radicals and a shift in the energy levels, leading to enhanced sensitivity for SWIR light detection. The optimized SWIR-OPTRs utilizing PolyTPD:BCF GSLs demonstrated high photoresponsivities for SWIR light detection.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Polymer Science
Chulyeon Lee, Woongki Lee, Hwajeong Kim, Youngkyoo Kim
Summary: In this study, low-voltage nonvolatile organic memory transistors with high charge-carrier mobility and excellent data-retention characteristics were demonstrated by using water-soluble reactive polymer blends as a gate-insulating memory layer. The optimized transistors showed significant improvements in hole mobility and data retention, making them promising for practical applications.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Hyunji Son, Taehoon Kim, Chulyeon Lee, Hwajeong Kim, Youngkyoo Kim
Summary: Organic phototransistors were developed using ambipolar polymers consisting of p-type and n-type indacenodithienothiophene (IDTT)-based conjugated polymers. The p-type polymer, PIDTT-8OBT, synthesized via Stille coupling reactions, demonstrated efficient light detection in p-channel mode for blue, green, and orange light and ambipolar characteristics when blended with an n-type polymer, PIDTT-NDI, covering a wide range of visible light up to 750 nm. The ambipolar OPTRs showed high photosensitivity in both p-channel and n-channel modes at different wavelengths, with a notable capability to detect deep red light not absorbed by the polymer blend.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Engineering, Electrical & Electronic
Taehoon Kim, Woongki Lee, Chulyeon Lee, Hwajeong Kim, Youngkyoo Kim
Summary: Organic phototransistors with a polymer blend gate sensing layer were fabricated for near infrared light detection. The devices showed improved performance upon illumination with near infrared light, with increased photosensitivity and photoresponsivity corresponding to higher content of the NIR-absorbing conjugated polymer in the polymer blend gate sensing layer.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
Hyunji Son, Yeonhwa Cho, Hwajeong Kim, Youngkyoo Kim
Summary: This study reports the development of semi-transparent organic phototransistors (OPTRs) for the detection of specific near-infrared (NIR) light used in LiDAR systems. The OPTRs consist of a sensing channel layer made of a specific polymer and employ special electrode materials to achieve semi-transparency. The results show that the devices can operate as p-channel transistors and are sensitive to the NIR light. Further optimization of device stability can lead to practical applications in LiDAR systems.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Yeonhwa Cho, Saebom Lee, Taehoon Kim, Hwajeong Kim, Dong-Ik Song, Youngkyoo Kim
Summary: In this study, NIR-OLDRs that can sense near infrared light have been reported. The devices are fabricated with a planar geometry using PDPP-8OBT as the active layer. The NIR-OLDRs exhibit excellent sensitivity to the incident intensity of 905 nm NIR light and show improved performance after annealing at 150 degrees C.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Polymer Science
Woongki Lee, Chulyeon Lee, Hwajeong Kim, Youngkyoo Kim
Summary: This work reports that ultrathin polymeric films doped with organic acid molecules can act as an electron-transporting interfacial layer in polymer:nonfullerene solar cells, improving the power conversion efficiency of the cells.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Sooyong Lee, Hwajeong Kim, Youngkyoo Kim
Summary: In this study, we demonstrate that the hole injection characteristics of phosphorescent OLEDs can be greatly improved by introducing a Lewis acid-doped conjugated polymer nanolayer. The presence of the conjugated polymer nanolayer leads to enhanced luminance and current efficiency in the OLEDs.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Chulyeon Lee, Woongki Lee, Myeonghun Song, Hwajeong Kim, Youngkyoo Kim
Summary: Organic field-effect transistors (OFETs) were fabricated using an n-type naphthalenediimide-based conjugated polymer (N2200) as the channel layer and poly(methyl methacrylate) (PMMA)/poly(vinyl alcohol) (PVA) as the gate insulating layer. The N2200/PMMA/PVA triple-layer OFETs operated in n-channel mode at low voltages (<= 5 V) and achieved an electron mobility of approximately 0.63 cm2/Vmiddots at a drain voltage of 5 V. The drain current of the OFETs increased gradually with the temperature of the channel region from 25 degrees C to 80 degrees C, while no shift in threshold voltage was observed. The devices exhibited excellent thermal sensing performances during repeated approaching/retracting tests using a heat source.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Yeonhwa Cho, Taehoon Kim, Woongki Lee, Hwajeong Kim, Youngkyoo Kim
Summary: Here, we present the fabrication and characterization of ambipolar organic phototransistors (OPTRs) with sensing channel layers of a conjugated terpolymer, PDPP-8OBT-NDI. The OPTRs exhibited well-balanced ambipolar characteristics at a wide voltage range and showed high photosensitivity in the near-infrared (NIR) region. The devices also displayed stable and reproducible photocurrent responses under continuous NIR light illumination and optical on/off modulation.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Martina Rimmele, Zhuoran Qiao, Julianna Panidi, Francesco Furlan, Chulyeon Lee, Wen Liang Tan, Christopher R. McNeill, Youngkyoo Kim, Nicola Gasparini, Martin Heeney
Summary: The dramatic improvement of the PCE of organic photovoltaic devices has been driven by the development of new polymer donor materials and non-fullerene acceptors. A new approach was reported to introduce various solubilizing groups into a benzo[c][1,2,5]thiadiazole acceptor comonomer, allowing for the preparation of a library of donor polymers for rapid screening of properties and performance. The donor polymer FO6-T emerged as the optimal material, exhibiting good solubility and achieving high PCE, making it suitable for large-scale applications.
MATERIALS HORIZONS
(2023)
Article
Green & Sustainable Science & Technology
Woongki Lee, Hwajeong Kim, Youngkyoo Kim
Summary: The thermoelectric characteristics of Polytriarylamine-Lewis acid complex films were investigated using a horizontal device structure. By doping Poly[N,N '-bis(4-butylphenyl)-N,N '-bis(phenyl)benzidine] (PolyTPD) with tris(pentafluorophenyl)borane (BCF) through Lewis acid-base reactions, PolyTPD:BCF films were fabricated. The resulting films were used to construct horizontal type organic thermoelectric devices (OTEDs).
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2023)
Article
Chemistry, Physical
Hyunji Son, Woongki Lee, Sooyong Lee, Hwajeong Kim, Youngkyoo Kim
Summary: This study reports the water-dipping effect of polymeric interfacial layers on the performance of inverted-type polymer solar cells. The results show that water-dipped bPEI layers can greatly increase the open circuit voltage and short circuit current density of the cells, leading to improved power conversion efficiency.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Engineering, Electrical & Electronic
Taehoon Kim, Chulyeon Lee, Woongki Lee, Hwajeong Kim, Youngkyoo Kim
Summary: In this study, the authors demonstrate the fabrication and characteristics of near-infrared light-sensing organic light-dependent resistors (OLDRs), or organic photoresistors (OPRTs), made of solution-processed NIR light-absorbing films. The devices exhibit significant reduction in electrical resistance upon NIR light illumination and show sensitivity to the intensity of NIR light.
ACS APPLIED ELECTRONIC MATERIALS
(2022)