Review
Chemistry, Multidisciplinary
Larry Lueer, Rong Wang, Chao Liu, Henry Dube, Thomas Heumueller, Jens Hauch, Christoph J. Brabec
Summary: This review discusses approaches to improve the power conversion efficiency of organic photovoltaic devices by minimizing the driving force required for charge separation. The factors influencing charge separation and the use of high throughput workflows are highlighted.
Article
Chemistry, Multidisciplinary
Fengtao Yu, Chuangye Li, Wanru Li, Zhiwu Yu, Zhenzhen Xu, Yan Liu, Bo Wang, Bing Na, Jianding Qiu
Summary: Adsorption-photocatalysis technology based on covalent organic frameworks (COFs) has been developed as an alternative method for uranium extraction from seawater. In this study, three donor-acceptor olefin-linked COFs containing amidoxime units were synthesized using a pi-skeleton engineering strategy, which significantly reduced the binding energy of excitons (E-b) and enhanced the photocatalytic activities. Furthermore, under visible light irradiation, a high photo-enhanced uranium extraction capacity was achieved from natural seawater without the use of sacrificial reagents.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Guang Chen, Zi-Dan Zhang, Ya-Xian Liao, Ze Zhang, Ye-Zi You
Summary: By introducing amino-cyano functional groups into carbon nitride, this study effectively dissociated excitons into electrons and holes, reducing the exciton binding energy and increasing the efficiency of photocatalytic hydrogen production.
Article
Chemistry, Multidisciplinary
Pengwei Li, Linfang Yan, Qingli Cao, Chao Liang, He Zhu, Sihui Peng, Yongpeng Yang, Yuncai Liang, Rudai Zhao, Shuangquan Zang, Yiqiang Zhang, Yanlin Song
Summary: Efficient exciton dissociation and charge transfer can be achieved in low-dimensional Ruddlesden-Popper (LDRP) perovskite by introducing gamma-aminobutyric acid (GABA) as a spacer. GABA forms hydrogen bonds to link adjacent spacing sheets, leading to charges localized in the van der Waals gap and constructing a charged-bridge for charge transfer. The GABA-based solar cell shows a champion power conversion efficiency (PCE) of 18.73% with enhanced carrier transport properties, and it also exhibits excellent long-term stability under continuous illumination and elevated temperature.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhipeng Miao, Qingli Cao, Sihui Peng, He Zhu, Fangfang Yuan, Yuncai Liang, Ting Zhang, Rudai Zhao, Pengwei Li, Yiqiang Zhang, Yanlin Song
Summary: LD Dion-Jacobson (LDDJ) perovskite constructed with cystamine as a ligand improves carrier properties and achieves higher conversion efficiency in low-dimensional perovskite solar cells (PSCs). Disulfide bonds play a significant role in charge localization and reducing charge transfer anisotropy.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ming Yao, Gang Xu, Kuanzhen Tang, Mingtao Zhang, Binbin Zhang, Jinmeng Zhu
Summary: The electronic structures and exciton properties of HgI2, CH3NH3HgI3, and (CH3NH3)2HgI4 were studied. CH3NH3HgI3 and (CH3NH3)2HgI4, which are organic-inorganic hybrids, showed lower dimension and higher band gap compared to HgI2, leading to significant excitonic properties. The effective masses of electrons and holes were predicted, and the exciton binding energy at room temperature was calculated. CH3NH3HgI3 and (CH3NH3)2HgI4 exhibited strong charge localization and high exciton binding energy, while HgI2 had low exciton binding energy. The presence of exciton absorption was confirmed through UV-vis diffuse reflectance spectra, and the exciton energy levels were determined by combining the spectra with the calculated binding energy. Notably, CH3NH3HgI3 and (CH3NH3)2HgI4 showed exciton luminescence peaks at 468 nm and 419 nm, respectively, indicating their potential applications in high-light-yield scintillators and light-emitting devices.
Article
Chemistry, Multidisciplinary
Xiaoxiao Yu, Shuyao Tian, Fengtao Zhang, Guangpeng Gao, Chen Zhang, Yi Han, Siyu Ji, Hui Guo, Xu-Hui Jin
Summary: Metal-free conjugated polymer photocatalysts offer a promising and environmentally friendly option for the photoreduction of CO2 to high value-added chemicals. By altering the number of acetylene units in the linkers, the exciton binding energy of the 2D conjugated polymers can be fine-tuned, resulting in enhanced photocatalytic activity for CO2 reduction.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Review
Materials Science, Multidisciplinary
Kameron R. Hansen, John S. Colton, Luisa Whittaker-Brooks
Summary: This review article discusses the pros and cons of different measurement techniques for determining the exciton binding energy (Eb). It emphasizes the discrepancies between different techniques and provides approximate values for the Eb of various materials based on extensive research.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Andre L. M. Freitas, Jose A. Souza
Summary: We demonstrate the formation of microwires and 2D layered morphologies from 3D MAPbBr(3) microcubes through a dissociation-recrystallization process assisted by water. The study reveals that controlling water and organic molecules in the precursor solution can change the optical properties and exciton dynamics, as well as influence trap- and excito-assisted recombination life-times.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Yongxu Hu, Li Yu, Yinan Huang, Zhongwu Wang, Shuguang Wang, Xiaosong Chen, Deyang Ji, Huanli Dong, Jie Li, Yajing Sun, Liqiang Li, Wenping Hu
Summary: A new narrow band gap organic small molecule semiconductor, DPP-T-TPA, with low exciton binding energy and small activation energy, has been designed and synthesized for simultaneous and distinguishable detection of light and temperature in organic phototransistors. The semiconductor exhibits thermal-enhanced photo-electric response due to its low exciton binding energy and distinct thermal-dependence of charge carrier and exciton.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Physics, Multidisciplinary
Hamidreza Simchi
Summary: This study focuses on dark excitons at the interface of sharp lateral heterostructure of two-dimensional transition metal dichalcogenides (TMDs). By introducing a low-energy effective Hamiltonian model, the energy dispersion relation of exciton is determined and its dependency on material properties and spin-orbit coupling strengths is shown. The geometrical structure effect of the interface, as a pseudo-spin-orbit coupling, should be considered in calculating the binding energy of exciton. The binding energy of exciton is found to depend on its distance from the interface line, with different values for exciton near the interface and far enough from the interface.
Article
Materials Science, Multidisciplinary
Kameron R. Hansen, C. Emma McClure, Daniel Powell, Hao-Chieh Hsieh, Laura Flannery, Kelsey Garden, Edwin J. Miller, Daniel J. King, Sami Sainio, Dennis Nordlund, John S. Colton, Luisa Whittaker-Brooks
Summary: This study investigates the intrinsic differences between lead and tin metal halide perovskites (MHPs) using the spectroscopic isolation of excitons in 2D MHPs. The results show that tin MHPs have larger polaron binding energy and lower exciton binding energy compared to lead MHPs, and their excitons exhibit Frenkel-like characteristics.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xuecheng Guo, Ganggang Li, Jingli Lou, Kongqi Chen, Ruishan Huang, Dezhi Yang, Han Zhang, Zhiming Wang, Ben Zhong Tang
Summary: In this study, a near-ultraviolet emitter with hot-exciton property is designed, and high-efficiency and low roll-off OLED devices are fabricated. Green phosphorescent OLED devices based on the emitter are also fabricated, showing outstanding performances.
Article
Chemistry, Physical
Guangyuan Gao, Xiujuan Wang, Ling Chen, Thomas Baumgartner, Xiaoming He
Summary: The study developed new conjugated polymers with BMP units for lithium-ion batteries, demonstrating superior performance and stability. The redox-active BMP units showed impressive potential for constructing high-performance battery materials.
CHEMISTRY OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Chinatsu Satoh, Takuya Okada, Taku Oono, Tsubasa Sasaki, Takahisa Shimizu, Hirohiko Fukagawa
Summary: A simple equation describing the minimum voltage required for OLED operation is reported, which takes into account the bandgap of the emitter and other relevant energies. It is found that the minimum voltage required for OLED operation is at least 0.7 V lower than the emitter's bandgap divided by the elementary charge, thanks to the relatively high exciton binding energy of organic materials. Based on these findings, D/A molecules are designed for ultra-low-voltage operation of OLEDs, and green and blue OLEDs emitting light at approximately 1.5 V are achieved through triplet-triplet annihilation photon upconversion.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
S. Kraner, R. Scholz, F. Plasser, C. Koerner, K. Leo
JOURNAL OF CHEMICAL PHYSICS
(2015)
Article
Materials Science, Multidisciplinary
Stefan Kraner, Johannes Widmer, Johannes Benduhn, Ellen Hieckmann, Till Jaegeler-Hoheisel, Sascha Ullbrich, Daniel Schuetze, K. Sebastian Radke, Gianaurelio Cuniberti, Frank Ortmann, Melanie Lorenz-Rothe, Rico Meerheim, Donato Spoltore, Koen Vandewal, Christian Koerner, Karl Leo
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2015)
Article
Materials Science, Multidisciplinary
S. Kraner, C. Koerner, K. Leo, E. Bittrich, K. -J. Eichhorn, Y. Karpov, A. Kiriy, M. Stamm, K. Hinrichs, M. Al-Hussein
Article
Chemistry, Physical
Stefan Kraner, Giacomo Prampolini, Gianaurelio Cuniberti
JOURNAL OF PHYSICAL CHEMISTRY C
(2017)
Article
Energy & Fuels
Stefan Kraner, Lukas Schmidt-Mende
Summary: The stability of organic solar cells is a major challenge for large scale mass production. By introducing an all-in-one donor-acceptor system and optimizing the molecular volume, the stability and power conversion efficiency of the cells can be improved.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Nanoscience & Nanotechnology
Timo Raab, Tobias Seewald, Stefan Kraner, Lukas Schmidt-Mende
Summary: This study investigates the influence of 1-chloronaphtalene (CN) on the spin coating of Y6:PM6 solar cells dissolved in chloroform. The film formation of Y6:PM6 can be divided into two parts in the presence of CN, with one part related to the evaporation of chloroform and the other part related to the evaporation of CN. Even at low CN concentration, the film formation is not completed for several minutes after the spin coating process. The removal of CN can be achieved by spin coating the electron transport layer PDINN from methanol, resulting in comparable performance to solar cells with more common CN concentrations.