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排序方式: 共有481条查询结果,搜索用时 234 毫秒
81.
The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells,have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells(PSCs). The power conversion efficiencies(PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices. 相似文献
82.
83.
We have designed and synthesis a new compound of zinc‐porphyrin bearing four pyrene groups (ZnP‐t‐P(py)4) and prepared a new hybrid materials of ZnP‐t‐P(py)4 with graphene oxide (GO) via non‐covalent interactions. The ZnP‐t‐P(py)4, along with four pendant pyrene entities ZnP‐t‐P(py)4, stacking on the (GO) surface due to π‐ π interactions, has been revealed by AFM measurements. FTIR, UV‐vis absorption confirm the non‐covalent functionalization of the GO. Raman spectral measurements revealed the electronic structure of the GO to be intact upon hybrid formation. In this donor‐acceptor nanohybrid, the fluorescence of photoexcited ZnP‐t‐P(py)4 is effectively quenched by a possible electron‐transfer process. The fluorescence and photoelectrical response measurements also showed that this hybrid may act as an efficient photoelectric conversion material for optoelectronic applications. 相似文献
84.
Dr. Kerim Samedov Dr. Yilmaz Aksu Prof. Dr. Matthias Driess 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(25):7766-7779
The syntheses and structural elucidation of dimeric [Sn(OCyHex)2] ( 1 ), its corresponding (cyclohexoxy)alkalistannates(II) [{M(OCyHex)3Sn}2] (M=Li ( 2 ), Na ( 3 ), K ( 4 )), and of the first heteroleptic heterotermetallic Li/In/Sn–haloalkoxide clusters [X2In{LiSn2(OCyHex)6}] (X=Br ( 5 ), Cl ( 6 )) with a double seco‐norcubane core are reported. They represent suitable precursors for new amorphous indium tin oxide (ITO) materials as transparent conducting oxides with drastically reduced concentrations of expensive indium, while maintaining their high electrical performance. In fact, compounds 5 and 6 were successfully degraded under dry synthetic air at relatively low temperature, resulting in new semiconducting tin‐rich ITOs homogeneously dispersed in a tin oxide/lithium oxide matrix. The obtained particles were investigated and characterised by different analytical techniques, such as powder XRD, IR spectroscopy, SEM, TEM and energy‐dispersive X‐ray spectroscopy (EDX). The analytical data confirm that the final materials consist of tin‐containing indium oxide embedded in an amorphous tin oxide matrix. The typical broadening and shift of the observed indium oxide reflections to higher 2θ values in the powder XRD pattern clearly indicated that tin centres were successfully incorporated into the In2O3 lattice and partially occupied In3+ sites. Investigations by EDX mapping proved that Sn was homogeneously distributed in the final materials. Thin‐film field‐effect transistors (FETs) were fabricated by spin‐coating of silicon wafers with solutions of 5 in toluene and subsequent calcination under dry air (25–700 °C). The FETs prepared with precursor 5 exhibited excellent performances, as shown by a charge‐carrier mobility of 6.36×10?1 cm2 V?1 s (calcination at 250 °C) and an on/off current ratio of 106. 相似文献
85.
针对机动平台光电跟踪系统跟踪目标需具备较强动态抗扰能力的问题,提出了一种将包含了非线性跟踪微分器、扩张状态观测器、非线性状态误差反馈三个环节的结构完整的自抗扰控制器用于光电跟踪伺服系统的速度环的思路。针对某单轴稳定转台设计了二阶自抗扰控制器,并进行了仿真研究。结果表明,该控制器对外扰变化及系统模型不确定性具有良好的鲁棒性和适应性,且能有效抑制系统中存在的非线性因素的影响。 相似文献
86.
Dr. Pengkun Wei Yang Yang Hongzhi Kang Zewei Hao Prof. Donggang Guo Prof. Lu Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13725-13729
As one of the promising clean and renewable technologies, water splitting has been a hot topic, especially the half-reaction of oxygen evolution reaction (OER) due to its sluggish and complex kinetics. Hence, Fe-doped NiCo2O4 nanobelts were designed and prepared as catalysts toward OER. By increasing the Fe amount, the catalytic performances of the as-synthesized products went up and then decreased. Profiting from the synergistic effect between Fe atom and NiCo2O4, all the Fe-NiCo2O4 catalysts exhibited superior catalytic activities to the corresponding NiCo2O4. In addition, the characteristic nanobelt architecture facilitates the conduction of electrons and the exposure of active sites. With the optimal Fe content, the 9.1 % Fe-NiCo2O4 yielded the smallest overpotential and Tafel slope among the catalysts, distinctly lower than that of RuO2. 相似文献
87.
Lisa M. S. Stiegler Tobias Luchs Prof. Dr. Andreas Hirsch 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(39):8483-8498
The current state of the hierarchical chemical functionalization of inorganic nanoparticles (NPs) by shell-by-shell (SbS)-assembly of organic layers around the NP cores is summarized. This supramolecular functionalization concept is based on two steps: 1) the covalent grafting of a first ligand–shell consisting of, for example, long chain phosphonic acids and 2) the noncovalent interdigitation of amphiphiles forming the second ligand shell. The latter process is guaranteed predominantly by solvophobic interactions. These highly order organic–inorganic hybrid architectures are currently an emerging field at the interface of synthetic chemistry, nanotechnology, and materials science. The doubly functionalized NPs display tunable materials properties, such a controlled dispersibility and stability in various solvents, highly efficient trapping of guest molecules in between the ligand shells (water cleaning) as well as compartmentalization and modification of electronic interactions between photoactive components integrated in such complex nano-architectures. Such SbS-functionalized NPs have a high potential as water-cleaning materials and also some first prototype applications as biomedicinal therapeutics have been presented. 相似文献
88.
Mircea Bulinski 《Molecules (Basel, Switzerland)》2021,26(10)
Polyvinyl alcohol is unique among polymers. Apart from its preparation, it is not built up in polymerization reactions from monomers, unlike most vinyl-polymers, and it is biodegradable in the presence of suitably acclimated microorganisms. It is an environmentally friendly material for a wide range of applications, from medical ones, based on its biocompatibility, to integrated optics. This paper reviews, in addition to the preparation and optimization of films of polyvinyl alcohol doped with different metal species, the role of dopants and doping technologies in the involved electronic mechanism. The optical properties were studied by UV-VIS-IR, Mössbauer spectroscopy, and other measurement techniques, with applications such as real-time holography, microlasers, optical sensors or nanophotonics in mind. 相似文献
89.
ABSTRACTIn this work, seven novel sensitisers with the donor-acceptor-π-spacer-acceptor (D-A-π-A) structure were designed based on the C219 dye by introducing different electron-withdrawing substituents, and their photovoltaic parameters were predicted by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations coupled with the Marcus charge transfer model. Results showed that the introduction of electron-withdrawing substituents can narrow the HOMO–LUMO gap, and remarkably enhance the dye's sunlight absorption. By exactly estimating the charge transfer rates and efficiency in electron injection and recombination processes, the photoelectric conversion efficiency (PCE) for the C219 dye was estimated to be about 7.4% under the standard AM 1.5G solar radiation, which is in excellent agreement with its measured value of 7.6%, suggesting that our calculation scheme is reliable. Moreover, we predicted that the PCE values for most designed dyes are over 10%, indicating that the molecular design strategy used by us in this work is reasonable. Especially, the PCE of dye 1, and 4 were predicted to be as high as 13.0% and 15.7% respectively, illuminating that the –CF3 and –CN are excellent substituents. Totally, our results revealed that the dye 1 and 4 are potential candidates as efficient sensitisers, and worth further study by experiments. 相似文献
90.
The present paper proposes a modification of a simple optoelectronic architecture (A. Bergeron et al.: Appl. Opt. 33 (1994) 1463) for carrying out optical thresholding operations. The threshold operation is achieved by means of a feedback loop. The setup is modified by inserting an attenuator adapted in each iteration to the total incident energy measured by an intensity detector. The proposed architecture does not need an additional light source, assures translation invariance and does not break the beam propagation path. The adaptive attenuator permits working under different lighting conditions (illumination, partially occluded objects, etc.). This kind of architecture is suitable for an optical pattern recognition task, optical neural network or optical associative memory. Application of the modified thresholder to the recognition task based on an optical correlator is reported. 相似文献