CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Yuqi Fan,Qi Liu,Zilong Zhang,Shui-Yang Lien,Yi Xie,Wanzhen Liang,Peng Gao
Lead-free halide double perovskites (LFDPs) arouse great interest as environmentally friendly substitutes to the state-of-the-art lead halide perovskites. However, most halide LFDPs feature large bandgaps that afford weak visible-light absorption. Herein, we synthesized and systemically studied the single-crystallographic, physical–chemical, band structural, and electronic properties of a series of multidimensional Au-based lead-free hybrid polymorphs, [(NH3CH3)2(AuI4)(AuI2)], [(NH2CHNH2)(AuI4)(AuI2)], [NH3(CH2)nNH3][(AuI4)2] (n = 2, 3), [NH3(CH2)nNH3][(AuI4)(I3)] (n = 4, 5, 6), and [NH3(CH2)nNH3]2[(AuI4)(AuI2)(I3)2] (n = 7, 8, 9). Among these two-dimensional (2D) perovskite-related and zero-dimensional nonperovskite polymorphs, we found an abnormal variation of structural dimensionality with increasing the size of A-site cations. These polymorphs displayed ultrabroad absorption ranges (200–1300 nm) and tunable low indirect bandgaps (0.93–1.18 eV). Combined single-crystallography and Hall effect measurements demonstrate that the I3– conduces to the formation of 2D perovskite structures related by connecting with the (AuI4)− sheets and also the charge transport properties. Consequently, [NH3(CH2)5NH3][(AuI4)I3] and [NH3(CH2)8NH3]2[(AuI4)(AuI2)(I3)2] showed high spectroscopic limited maximum efficiencies of 28.4 and 20.5%, respectively, with a film thickness of 500 nm. Our findings bring the Au-based polymorphs to the forefront of study on lead-free low-bandgap perovskites for optoelectronics and reveal the unique rule of dimensionality engineering in such materials.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Rong Wang,Qingfu Cai,Yunyang Zhu,Zhen Mi,Weijun Weng,Yicheng Liu,Jiaxun Wan,Jianhua Hu,Changchun Wang,Dong Yang,Jia Guo
Low-bandgap covalent organic frameworks (COFs) emerge as one of the most intriguing conjugated polymers for the development of electronic devices, while they often lack desirable electron affinity, thereby compromising the activity and stability in electrochemical transformation. Here, we report an n-type semiconducting two-dimensional (2D) COF, featuring a low bandgap (1.36 eV) and strong electron affinity (4.41 eV) as well as high crystallinity and porosity. The columnar stacking array of the benzobisthiadiazole moiety in 2D COFs plays a critical role in elevating electroactivity. It not only leads to the outstanding electrical conductivity and air stability upon reductive doping but also enables the boost of transformation kinetics for polysulfides on the separators of lithium–sulfur batteries causing a higher capacity and better cycling performance. The design strategy underpins the versatile development of electroactive COF materials with desirable electronic properties and promotes their applicability in energy storage and electronics.
研究领域:
材料科学
·
能源存储
·
电子器件
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Yan Zhang,Lingqian Kong,Hongmei Du,Jinsheng Zhao,Yu Xie
Three novel donor-accept type electrochromic polymers with very low band gap, namely PMFTTP, PMFBTTP and PMFMOTTP, were prepared via electrochemical polymerization , employing 2,3-bis(5-methylfuran-2-yl)thieno[3,4- b ]pyrazine as the acceptor units and thiophene , butylthiophen and methoxythiophen as the donor units, respectively. All the polymers were comparatively studied by cyclic voltammetry (CV), scanning electron micrographs (SEM), UV–vis-NIR spectroscopy and colorimetry . The results revealed that PMFTTP and PMFBTTP showed obvious color change from green color to brown in the oxidation process , while PMFMOTTP exhibited color change from brick red to dark gray. And the three polymers possessed very low optical band gaps in the following order: PMFTTP (1.23 eV) > PMFBTTP (0.88 eV) > PMFMOTTP (0.74 eV), which demonstrated the different election-donating ability of thiophene or its derivatives. The electrochromic kinetic investigations manifested that the polymers presented satisfactory optical contrasts (ΔT%) in the near infrared region (NIR), which were 35%, 67% and 60% for PMFTTP, PMFBTTP and PMFMOTTP, respectively. Moreover, the polymers also displayed short switching times (lower than 1 s at any wavelengths), high coloration efficiencies (around about 200 cm 2 /C) and outstanding robust stabilities, suggesting the probability of being the promising candidates for the electrochromic devices. In summary, the above positive results, especially the neutral green color and the very low band gap, had important theoretical significance for the application and development of electrochromic polymers.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 8
·1554
·
IF 4.967
Yiping Guo,Zeyang Li,Mengzhen Sha,Ping Deng,Xinyu Lin,Jun Li,Liang Zhang,Hang Yin,Hongbing Zhan
A simple wide-bandgap conjugated polymer based on indoloquinoxaline unit (PIQ) has been newly designed and synthesized via cheap and commercially available starting materials. The basic physicochemical properties of thePIQhave been investigated.PIQpossesses a broad and strong absorption band in the wavelength range of 400~660 nm with a bandgap of 1.80 eV and lower-lying highest occupied molecular orbital energy level of −5.58 eV. Polymer solar cells based onPIQand popular acceptor Y6 blend display a preliminarily optimized power conversion efficiency of 6.4%. The results demonstrate indoloquinoxaline is a promising building unit for designing polymer donor materials for polymer solar cells.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2017
·
IF 4.018
Zelin Li,Zidong Li,Xiaoli Zhao,Tong Zhang,Fan Wu,Dalei Yang,Xiaoniu Yang
Nickel acetate (Ni(Ac) 2 ) was successfully introduced to the low band-gap system for the first time and incorporated as the anode interlayer in conventional polymer solar cells (PSCs). For PBDT-TS1/PC 71 BM system, the device based on as-prepared Ni(Ac) 2 performs a lower power conversion efficiency (PCE) of 6.26% in comparison to that of PEDOT:PSS-based device (6.56%). After appropriate pre-bias treatment, the device efficiency rapidly increases to 7.27%, which is 11% and 16% higher than that of PEDOT:PSS- and as-prepared Ni(Ac) 2 -based device, respectively, due to the suppressed charge recombination and enhanced hole transport at anode interface. More importantly, device with pre-bias treated Ni(Ac) 2 as anode interlayer exhibits significantly improved lifetime in N 2 atmosphere. The Ni(Ac) 2 -based PSCs could maintain almost 85% of its original PCE after 200 h, while PEDOT:PSS-based PSCs only retains 60% of its original efficiency. This work demonstrates that the low-cost Ni(Ac) 2 is an ideal anode interlayer material, which could simultaneously improve the device efficiency and stability, to replace the widely used and high-cost PEDOT:PSS.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 17
·4984-4992
·
IF 5.368
Zhenguo Wang,Jie Zhao,Ying Li,Qiang Peng
A low band-gap copolymer, PDTS-FID, containing alternating dithienosilole (DTS) donor blocks and fluorinated isoindigo (FID) units, and its non-fluorinated counterpart, PDTS-ID, have been synthesized and characterized for photovoltaic applications. Compared to PDTS-ID, its fluorinated counterpart, PDTS-FID, exhibits broader and stronger absorption, lower-lying HOMO and LUMO energy levels, and higher hole mobility, resulting in an improved open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF) and power conversion efficiency (PCE). The positive effects were attributed to the fluorinated isoindigo block which favored a linear and planar conformation, giving rise to better backbone packing of the related copolymer, which was also confirmed by theoretical calculations (DFT). The conventional and inverted devices were fabricated and evaluated to explore the photovoltaic properties of the resulting copolymers. The best performance of 5.79% PCE was obtained from an inverted polymer solar cell (PSC) using PDTS-FID as the donor material, with a Voc of 0.84 V, a Jsc of 10.77 mA cm−2 and a FF of 0.64. These low band-gap copolymers could be expected to be promising donor materials for application in PSCs.
研究领域:
材料科学
·
有机光电材料
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2012
·Vol. 3
·期 10
·2933-2940
·
IF 5.321
Qiang Peng,Yingying Fu,Xiangju Liu,Jun Xu,Zhiyuan Xie
A novel acceptor of 2,1,3-benzothiadiazole (BT) with diphenylamine-vinylene side chains was firstly designed and synthesized for building efficient low bandgap (LBG) photovoltaic copolymers in this paper. Based on benzo[1,2-b;3,4-b]dithiophene and the designed new BT acceptor, two dimensional (2D) like conjugated copolymers have been prepared by Stille coupling polymerization. The resulting copolymers were characterized by NMR, elemental analysis, gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis. UV-vis absorption and cyclic voltammetry measurements indicate that these copolymers have good optical and electrochemical properties. A copolymer with thiophene modified benzo[1,2-b;3,4-b]dithiophene exhibits better light harvesting and a smaller bandgap of the two copolymers. The electronic structures of the model compounds were also studied by DFT calculations at the B3LYP/6-31G* level. The polymer solar cells (PSCs) were fabricated and measured with a typical structure of ITO/PEDOT:PSS/copolymer:PCBM/Ca/Al. The primary results showed that the device based on the copolymer with thiophene modified benzo[1,2-b;3,4-b]dithiophene had a higher efficiency of 1.88%, attributed to the smaller bandgap and improved active film morphology. All the prepared copolymers are promising candidates for efficient PSCs with high Voc.
研究领域:
材料科学
·
有机电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Binhua Mei,Ju Bai,Yuhang Zhang,Yang Ma,Yanjun Hou,Shuhong Wang,Cheng Wang
Low-band gap semiconductor polymer materials play a crucial role in the field of organic optoelectronics. In this context, a series of low-band gap polymers containing thienopyrazine as the acceptor and cyclofluorene–bithiophene as the donor were synthesized and utilized in resistive random access memory (RRAM) devices. These memory devices consistently exhibit nonvolatile flash memory behavior. Remarkably, all three polymers demonstrate stability even after 1000 cycles without significant fluctuations. Notably, the three polymer-based devices also exhibit excellent ternary memory performance, with current ratios of 1:10 2.8 :10 4 , 1:10 1.3 :10 3.9 , and 1:10 1.8 :10 3.6 . Furthermore, the photoelectric properties of the three polymers and the conduction mechanisms of the memory devices were thoroughly discussed.
研究领域:
有机光电子学
·
材料科学
·
半导体器件
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2017
·
IF 9.466
Yunlong Ma,Meiqi Zhang,Yabing Tang,Wei Ma,Qingdong Zheng
The utilization of low bandgap copolymers has been considered as one of the most efficient ways to increase power conversion efficiencies (PCEs) of fullerene-based polymer solar cells (PSCs). However, an increase in the short-circuit current (JSC) value is usually counteracted by a decrease in the open-circuit voltage (VOC), which limits a further PCE enhancement of fullerene-based PSCs. As a result, nonfullerene acceptors with wide-range tunable energy levels are used as alternatives to the traditional fullerene acceptors to overcome the negative trade-off between the JSC and VOC. Here, a novel nonfullerene acceptor is developed by using an angular-shaped dithienonaphthalene flanked by electron-withdrawing 3-ethylrhodanine units via benzothiadiazole bridges. The obtained nonfullerene acceptor exhibits a high-lying lowest unoccupied molecular orbital level of −3.75 eV with enhanced absorption. In combination with a benchmark low bandgap copolymer (PTB7-Th), a high PCE of 9.51% with a large VOC of 1.08 V was achieved for the nonfullerene PSCs, demonstrating an extremely low energy loss of 0.50 eV, which is the lowest among all high-performance (PCE > 8%) polymer-based systems with similar optical bandgaps. The results demonstrate the bright future of our nonfullerene acceptor as an alternative to the fullerene derivatives for PSCs with large JSC and VOC values and improved device stability.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2012
·Vol. 18
·期 38
·12140-12151
·
IF 5.925
Qiang Peng,Siew-Lay Lim,Ivy Hoi-Ka Wong,Jun Xu,Zhi-Kuan Chen
Graphical 2D Photovoltaic copolymers : New benzothiadiazole acceptors with different conjugated arylvinylene side chains have been designed and used to build 2D-like low-bandgap copolymers (see figure). It was found that their optical and electrochemical properties can be easily modified by changing the structures of the conjugated arylvinylene side chains. The photovoltaic properties imply that all the prepared copolymers are promising candidates for roll-to-roll manufacturing of efficient polymer solar cells. A new series of 2,1,3-benzothiadiazole (BT) acceptors with different conjugated aryl-vinylene side chains have been designed and used to build efficient low-bandgap (LBG) photovoltaic copolymers. Based on benzo[1,2- b :3,4- b ′]dithiophene and the resulting new BT derivatives, three two-dimensional (2D)-like donor (D)–acceptor (A) conjugated copolymers have been synthesised by Stille coupling polymerisation. These copolymers were characterised by NMR spectroscopy, gel-permeation chromatography, thermogravimetric analysis and differential scanning calorimetry. UV/Vis absorption and cyclic voltammetry measurements indicated that their optical and electrochemical properties can be facilely modified by changing the structures of the conjugated aryl-vinylene side chains. The copolymer with phenyl-vinylene side chains exhibited the best light harvesting and smallest bandgap of the three copolymers. The basic electronic structures of D–A model compounds of these copolymers were also studied by DFT calculations at the B3LYP/6-31G* level of theory. Polymer solar cells (PSCs) with a typical structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrenesulfonate) (PSS)/copolymer:[6,6]-phenyl-C 61 (C 71 )-butyric acid-methyl ester (PCBM)/calcium (Ca)/aluminum (Al) were fabricated and measured under the illumination of AM1.5G at 100 mW cm −2 . The results showed that the device based on the copolymer with phenyl-vinylene side chains had the highest efficiency of 2.17 % with PC 71 BM as acceptor. The results presented herein indicate that all the prepared copolymers are promising candidates for roll-to-roll manufacturing of efficient PSCs. Suitable electronic, optical and photovoltaic properties of BT-based copolymers can also be achieved by fine-tuning the structures of the aryl-vinylene side chains for photovoltaic application.
研究领域:
材料科学
·
有机光电材料
✓ 已验证
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-10
·
IF 15.7
Liu Yuhui,Ma Tianshu,Wang Changlei,Yang Zhenhai,Zhao Yue,Wu Zhanghao,Chen Chen,Bao Yining,Zhai Yuhang,Jia Tianci,Chen Cong,Zhao Dewei,Li Xiaofeng
Low-bandgap (LBG) mixed tin-lead (Sn−Pb) perovskite solar cells (PSCs) suffer from inferior performance due to their high defect density. Conventionally, ethylenediammonium diiodide (EDADI) is used as a surface passivator to reduce defects and improve device photovoltaic performance, but it introduces severe hysteresis caused by excessive mobilized ions at the top interface. Here, we report a mobile ion suppressing strategy of using hydrazine monohydrochloride (HM) as a bulk passivator to anchor the free ions in LBG perovskites. The protonated hydrazine (N 2 H 5 + ) of HM formed hydrogen bonds with iodine (I – ) ions, while the chloride (Cl – ) ions occupied the I – vacancies, collectively impeding the migration of I – and thus mitigating the ion movement-induced hysteresis that arose from EDADI usage. The synergistic strategy of HM doping and EDADI post-treatment significantly suppresses the oxidation of Sn 2+ , decreases trap density, and inhibits rapid crystallization of perovskite. Consequently, we achieved a champion efficiency of 23.21% for LBG PSCs. Integrating these cells with wide-bandgap PSCs into all-perovskite tandem solar cells yields a high efficiency of 28.55% (certified 28.31%) with negligible hysteresis.
研究领域:
材料科学
·
能源科学
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）