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71.
人体指纹谱的初步分析 总被引:4,自引:2,他引:2
大量实验测试表明:人体正常指纹谱反映人体正常状态,而人体异常指纹谱则反映人体异常状态。本文对人体指纹谱的结构及其机理做了初步分析和讨论。 相似文献
72.
本文使用分子轨道从头算方法,在HF/6—31G和MP2/6—31G“水平下,计算了小硅化物SiXm的平衡几何和谐振子振动频率。理论值和实验值的比较表明,对于SiHm分子,实验的键长位于HF键长和MP2键长之间,而MP2振动频率更接近于实验的振动;率。对于SiClm分子,无论是键长还是振动频率HF值和MP2值都比较接近。对于SiFm分子,处于这两类的中间情况。关联作用随着X原子的原子序数的增加而减弱。 相似文献
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Huang Y Wang Y Sang G Zhou E Huo L Liu Y Li Y 《The journal of physical chemistry. B》2008,112(43):13476-13482
A polythiophene derivative with the simplest conjugated side chain, poly(3-hexy-1-enylthiophene) (P3HET), was synthesized by Stille self-coupling reaction. A comparative study of the newly synthesized polymer with poly(3-hexylthiophene) (P3HT), one of the most widely investigated optoelectronic materials, is presented. The effect of double bond (C=C) on the side chain toward thermal stability and optical and electronic properties was fully characterized by TGA, UV-vis absorption spectroscopy, photoluminescence spectroscopy, and cyclic voltammetry. The hole mobility of P3HET determined by the space-charge-limited current (SCLC) model is 6.7 x 10(-3) cm(2)/V s, which is comparable to P3HT with similar molecular weight and regularity and 1 order of magnitude higher than most conjugated-side-chain polythiophene derivatives. Polymer solar cells (PSCs) and field effect transistors (FETs) were fabricated respectively to exploit its potential applications in optoelectronic devices. 相似文献
78.
Wenjing Zhang Dr. Yue Wu Dr. Ruijie Ma Dr. Hongyu Fan Xiaoxiao Li Dr. Hang Yang Prof. Chaohua Cui Prof. Yongfang Li 《Angewandte Chemie (International ed. in English)》2023,62(43):e202309713
Regulating molecular packing and aggregation of photoactive layer is a critical but challenging issue in developing high-performance organic solar cells. Herein, two structurally similar analogues of anthra[2,3-b : 6,7-b′]dithiophene (ADT) and naphtho[1,2-b : 5,6-b′]dithiophene (NDT) are developed as solid additive to exploit their effect in regulating the molecular aggregation and π-stacking of photoactive layer. We clarify that the perpendicular arrangements of NDT can enlarge the molecular packing space and improve the face-on stacking of Y6 during the film formation, favoring a more compact and ordered long-range π-π stacking in the out-of-plane direction after the removal of NDT under thermal annealing. The edge-to-face stacked herringbone-arrangement of ADT along with its non-volatilization under thermal annealing can induce the coexistence of face-on and edge-on stacking of blend film. As a result, the NDT treatment shows encouraging effect in improving the photovoltaic performance of devices based on various systems. Particularly, a remarkable PCE of 18.85 % is achieved in the PM6 : L8-BO-based device treated by NDT additive, which is a significant improvement with regard to the PCE of 16.41 % for the control device. This work offers a promising strategy to regulate the molecular packing and aggregation of photoactive layer towards significantly improved performance and stability of organic solar cells. 相似文献
79.
Jinxin Wang Hao Zhang Shumu Li Caijun Ding Yongjie Zhao Xiuzhen Long Chang Wei Yanfang Wang Yongfang Li Lingyun Shen Prof. Shuxun Cui Prof. Wenjing Hong Prof. Mao Li 《Angewandte Chemie (International ed. in English)》2023,62(4):e202216838
The synthesis of crystalline polymer with a well-defined orientated state and a two-dimensional crystalline size beyond a micrometer will be essential to achieve the highest physical feature of polymer material but remain challenging. Herein, we show the synthesis of the crystalline unipolymer monolayer with an unusual ultrahigh modulus that is higher than the ITO substrate and high conductance by simultaneous electrosynthesis and manipulation. We find that the polymer monolayer has fully extended in the vertical and unidirectional orientation, which is proposed to approach their theoretically highest density, modulus, and conductivity among all aggregation formations of the current polymer. The modulus and current density can reach 40 and 1000 times higher than their amorphous counterpart. It is also found that these monolayers exhibit the bias- and length-dependent multiple charge states and asymmetrically negative differential resistance (NDR) effect, indicating that this unique molecular tailoring and ordering design is promising for multilevel resistive memory devices. Our work demonstrates the creation of a crystalline polymer monolayer for approaching the physical limit of polymer electronic materials and also provides an opportunity to challenge the synthetically iterative limit of an isolated ultra-long polymer. 相似文献
80.
Incorporation of Hexa‐peri‐hexabenzocoronene (HBC) into Carbazole–Benzo‐2,1,3‐thiadiazole Copolymers to Improve Hole Mobility and Photovoltaic Performance 下载免费PDF全文
Dr. Chen Gao Pei Jiang Keli Shi Di Ma Prof. Dr. Yongfang Li Prof. Dr. Gui Yu Prof. Dr. Xiaoyu Li Prof. Dr. Haiqiao Wang 《化学:亚洲杂志》2016,11(5):766-774
Hexa‐peri‐hexabenzocoronene (HBC) is a discotic‐shaped conjugated molecule with strong π–π stacking property, high intrinsic charge mobility, and good self‐assembly properties. For a long time, however, organic photovoltaic (OPV) solar cells based on HBC demonstrated low power conversion efficiencies (PCEs). In this study, two conjugated terpolymers, poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5′‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PCDTBT)‐ 5 HBC and PCDTBT‐ 10 HBC, were synthesized by incorporating different amounts of HBC as the third component into poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5′‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PCDTBT) through Suzuki coupling polymerization. For comparison, the donor–acceptor (D –A) conjugated dipolymer PCDTBT was also synthesized to investigate the effect of HBC units on conjugated polymers. The HBC‐containing polymers exhibited higher thermal stabilities, broader absorption spectra, and lower highest‐occupied molecular orbital (HOMO) energy levels. In particular, the field‐effect mobilities were enhanced by more than one order of magnitude after the incorporation of HBC into the conjugated polymer backbone on account of increased interchain π–π stacking interactions. The bulk heterojunction (BHJ) polymer solar cells (PSCs) fabricated with the polymers as donor and PC71BM as acceptor demonstrated gradual improvement of open‐circuit voltage (VOC) and short‐circuit current (JSC) with the increase in HBC content. As a result, the PCEs were improved from 3.21 % for PCDTBT to 3.78 % for PCDTBT‐ 5 HBC and then to 4.20 % for PCDTBT‐ 10 HBC. 相似文献