排序方式: 共有17条查询结果,搜索用时 31 毫秒
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Yuan Jun Zhang Chujun Chen Honggang Zhu Can Cheung Sin Hang Qiu Beibei Cai Fangfang Wei Qingya Liu Wei Yin Hang Zhang Rui Zhang Jidong Liu Ye Zhang Huotian Liu Weifang Peng Hongjian Yang Junliang Meng Lei Gao Feng So Shukong Li Yongfang Zou Yingping 《中国科学:化学(英文版)》2020,63(8):1159-1168
Recent advances in material design for organic solar cells(OSCs) are primarily focused on developing near-infrared nonfullerene acceptors, typically A-DA′D-A type acceptors(where A abbreviates an electron-withdrawing moiety and D, an electron-donor moiety), to achieve high external quantum efficiency while maintaining low voltage loss. However, the charge transport is still constrained by unfavorable molecular conformations, resulting in high energetic disorder and limiting the device performance. Here, a facile design strategy is reported by introducing the "wing"(alkyl chains) at the terminal of the DA′D central core of the A-DA′D-A type acceptor to achieve a favorable and ordered molecular orientation and therefore facilitate charge carrier transport. Benefitting from the reduced disorder, the electron mobilities could be significantly enhanced for the"wing"-containing molecules. By carefully changing the length of alkyl chains, the mobility of acceptor has been tuned to match with that of donor, leading to a minimized charge imbalance factor and a high fill factor(FF). We further provide useful design strategies for highly efficient OSCs with high FF. 相似文献
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光纤布拉格光栅在光纤系统中起着反射镜的作用,它在光纤通信和光纤传感技术中应用十分广泛[1].特别是近年发展起来的利用相位掩膜技术,对掺杂光纤芯径的紫外诱导轴向折射率变化来制备光栅[2],方法简单,适于大规模生产,更具有强大的生命力.伴随该技术的成熟与开发,已促进全光纤技术范围内的科学进步. 相似文献
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NH3在选择性催化还原NO过程中的吸附与活化 总被引:15,自引:0,他引:15
通过大量文献并结合自己的工作,以NH3在催化剂表面的阶段氧化脱氢为主线,分析归纳了选择性催化还原(SCR)反应机理和该体系中可能发生的NH3氧化副反应机理的联系和共性. 对于V2O5/TiO2催化剂,大部分学者认为SCR反应与Brnsted酸性位上的NH+4有关,中间体为NH+3(ads); 而少数学者认为SCR反应与Lewis酸性位上的NH3有关,中间体为NH2(ads). 对于其它SCR催化剂,普遍认可L酸性位上NH3活化脱氢形成的NH2(ads)既是SCR反应中间体,也是NH3氧化生成N2的中间体; NH3氧化生成N2O和NO的反应源于NH2(ads)的进一步脱氢. 尽管有关SCR反应中NH3的吸附位存在分歧,但从NH3吸附后活化的角度看, NH3无论吸附在L酸性位还是B酸性位,都先经过阶段氧化脱氢,然后再参与SCR反应. 由于反应中生成的H2O可能导致L酸向B酸转化,且该转化受反应温度影响,因此不同酸性位机理可能没有本质区别, SCR反应关键是NH3吸附位的氧化性. SCR活性取决于NH3在催化剂表面的吸附量和阶段氧化程度. 催化剂应能吸附足够的NH3, 这与其表面酸碱性有关; 吸附的NH3要能被活化脱氢且程度不宜太高,这与表面氧化还原性有关. 反应温度也会影响NH3的吸附量和活化程度,因此开发高效SCR脱硝催化剂的关键是根据反应温度调控其表面酸性和吸附位的氧化性. 相似文献
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NH3在V2O5/AC催化剂表面的吸附与氧化 总被引:6,自引:0,他引:6
将V2O5担载在活性焦(AC)上制得V2O5/AC催化剂,通过吸附脱附实验、程序升温脱附实验与原位质谱结合,对200 ℃下NH3在V2O5/AC催化剂表面的吸附和氧化行为进行了研究. 结果表明, AC具有吸附NH3和将NH3转化为NO的能力,这种能力可能源于两种活性位; 担载V2O5后,催化剂对NH3的吸附能力显著增强,并产生了新的NH3氧化产物N2, 但NH3氧化为NO的能力减弱; SO2在催化剂表面的吸附进一步增大了V2O5/AC对NH3的吸附量,这可能是因为硫铵盐的生成消除了催化剂将NH3氧化转化为NO和N2的能力. 当催化剂表面吸附的NH3接近饱和,即表面接近酸碱平衡后NH3才能被氧化为N2. NH3的几个氧化反应都主要依赖气相的O2, 催化剂自身的化合氧作用很小. 相似文献
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Yahui Liu Bowen Liu Chang-Qi Ma Fei Huang Guitao Feng Hongzheng Chen Jianhui Hou Lingpeng Yan Qingya Wei Qun Luo Qinye Bao Wei Ma Wei Liu Weiwei Li Xiangjian Wan Xiaotian Hu Yanchun Han Yaowen Li Yinhua Zhou Yingping Zou Yiwang Chen Yongfang Li Yongsheng Chen Zheng Tang Zhicheng Hu Zhi-Guo Zhang Zhishan Bo 《中国科学:化学(英文版)》2022,(2):224-268
During past several years,the photovoltaic performances of organic solar cells(OSCs)have achieved rapid progress with power conversion efficiencies(PCEs)over 18%,demonstrating a great practical application prospect.The development of material science including conjugated polymer donors,oligomer-like organic molecule donors,fused and nonfused ring acceptors,polymer acceptors,single-component organic solar cells and water/alcohol soluble interface materials are the key research topics in OSC field.Herein,the recent progress of these aspects is systematically summarized.Meanwhile,the current problems and future development are also discussed. 相似文献
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Zhe Li Can Zhu Jun Yuan Liuyang Zhou Wei Liu Xinxin Xia c Juan Hong Honggang Chen Qingya Wei Xinhui Lu Yongfang Li Yingping Zou 《Journal of Energy Chemistry》2022,(2):173-178
Balancing charge generation and low energy loss(Eloss), especially in the wide spectral absorption region is critical to obtain high-performance organic photovoltaics(OPVs). Therefore, Y11-M and Y11-EB are designed and synthesized through modifying alkyl chains on different nitrogen aromatic rings of the reported non-fullerene acceptor Y11. Although all the molecules have almost similar low band-gap(around 1.30 e V), Y11-M and Y11-EB exhibit wider absorption in 410–870 nm region. Eventually, the conventional devices based on Y11-M and Y11-EB possess more efficient charge generation with low Eloss(around 0.44 e V). In addition, outstanding efficiencies of 16.64% and 17.15% with the fill factor of 76.15% and 74.73% are obtained in PM6:Y11-M and PM6:Y11-EB-based devices, both higher than Y11:PM6. The results highlight the importance of rational alkyl chains optimization, and a good structureproperty relationship is established as well. 相似文献