Langmuir‐Blodgett films of a cellulose derivative containing porphyrins, porphyrin‐cellulose, were fabricated in order to construct a cellulose‐based molecular photocurrent generation system. On visible light illumination of the LB monolayer film deposited on an ITO electrode, anodic photocurrents were observed with a quantum yield of 1.6% at an applied potential of 0 V versus SCE, and 3.8–4.6% at 0.2–0.3 V versus SCE. These values indicate that the self‐quenching of the photoexcited porphyrins in the cellulose LB film was suppressed, while porphyrin moieties in the LB film had a densely packed structure. This is because the porphyrins are located at a distance of approximately 1.0 nm along the cellulose backbone.
A bio‐inspired graphene/Au@ZnO photoelectrode has been prepared via breath figure method, in which Au@ZnO nanospheres were uniformly distributed in the whole honeycomb film. The size of the honeycomb holes effects the light using efficiency. The honeycomb film with smaller holes in more ordered array shows better antireflective property. All the formed graphene/Au@ZnO honeycomb photoelectrodes show a fast, stable, and reversible response of photocurrent accompanied by each switch‐on and switch‐off event. Au@ZnO ‐modified graphene honeycomb film can combine the advantages of increased light harvesting provided by honeycomb structure, efficient charge separation from Au nanoparticles (NPs ), and efficient electron transfer provided by graphene. Au@ZnO ‐ modified graphene honeycomb film shows a two‐fold increase of photocurrent generation than ZnO ‐modified graphene honeycomb film and a three‐fold increase of photocurrent generation than Au@ZnO ‐modified graphene smooth film, respectively. The rational design and engineering of multi components with different functions in a hybrid bio‐inspired structure hold great promise for further efficient solar energy conversion devices. 相似文献
Langmuir-Blodgett (LB) film of a hemicyanine derivative, (E)-N-hexadecyl-4-[2-(4-dimethylaminophenyl)ethenyl]pyridinium bromide (Hc) was fabricated. The Langmuir film of Hc exhibited good transfer behaviour. Optical second harmonic generation from the LB film was measured. Macroscopic second-order susceptibilily, molecular hyperpolarizability and tilt angle for the molecules on a substrate were estimated to be 7.06×10-6 esu, 6.47×10-27 esu,and 31.6° respectively. 相似文献
We chose DPP‐BDT‐DPP {DPP=diketopyrrolopyrrole, BDT=4,8‐di‐[2‐(2‐ethylhexyl)‐thienyl]benzo[1,2‐b:4,5‐b′]dithiophene} as a model backbone and varied the anchoring groups [? C5H11, ? COOCH3, and ? SiCH3(OSiCH3)2] terminated on the N‐substituted alkyl‐chain spacer of the DPP units to study the effect of anchoring terminals on the morphology of blend film and on the device performances of bulk heterojunction solar cells. By replacing the nonpolar ? C5H11 anchoring terminal with the polar ? COOCH3 anchoring terminal leads to an enhancement in the short‐circuit current density (Jsc) (4.62 vs. 9.32 mA cm?2), whereas the value of Jsc sharply decreases to 0.45 mA cm?2 if the ? C5H11 anchoring terminal is replaced by a ? SiCH3(OSiCH3)2 group. The changes in Jsc are associated with changes in the π–π stacking distance (3.39→3.34 Å vs. 3.39→3.45 Å) and the phase size (50→20 nm vs. 50→>250 nm) through alteration of the anchoring group from ? C5H11 to ? COOCH3 versus from ? C5H11 to ? SiCH3(OSiCH3)2. Interestingly, the anchoring terminals bring about drastic changes in molecular orientations, which result in different out‐of‐plane hole transport. This is the first time this effect has been systemically demonstrated to improve photocurrent generation by manipulating the dipolar anchoring groups terminated on the alkyl‐chain spacer. 相似文献
Organic semiconductor devices with low energy consumption and excellent stability are highly desirable. Controlling the intermolecular alignment orientation by designing the molecular structure or optimization of the film preparation process is an alternative way to achieve this goal. In this paper, a new idea was proposed to realize the formation of an aligned monomolecular layer and multimolecular layer thin films on the electrode substrate by controlling the surface pressure of molecular layer on the liquid surface by LB technology. An amphiphilic π-conjugated D−A molecule was synthesized, and the influence of spin coating and LB technology on intermolecular ordered stacking in the film and the electrical memory performance were investigated. The results demonstrated that the film fabricated by LB technology has some advantages compared with that fabricated by spin-coating method, such as higher crystallinity, lower surface roughness and better-organized monomolecular and multimolecular layer, which significantly promoted the performance of the electrical memory device with lower power consumption and longer stability. 相似文献
Polarized UV-visible absorption spectroscopy was used to investigate the inplane orientation of the hemicyanine molecules in Y-type Langmuir-Blodgett(LB) multilayers. We demonstrated for the first time that the dipping-induced molecular alignment was enhanced significantly with increasing the layer number due to the interlayer interactions. Polarized UV nanosecond pulses were used to control the photoinduced reorientation of the hemicyanine molecules. Thermal-isotropic process was accompaniedd by dissocition of the H-aggregate in hemicyanine LB multilayers. 相似文献
Fullerene derivatives containing two or more [60]fullerene units may exhibit interesting properties1. There have been reported a limited number of organofullerenes with two or more cages, and the synthetic procedures are an oxidative coupling reaction of terminal alkynes2, bifunctional cycloaddition reactions such as diazo compounds3, dienes4 or (-amino acids and aldehydes 1, 3-dipolar cycloaddtion5, cyanogen di-N-oxide as a double 1, 3-dipole6. Oxo- and methylene-bridged [60]fullerene dimers … 相似文献
Up to now, the investigations of the chemistry of biliverdin and its analogs has been limited in organic solvents1-4. There is no report on organized molecular films of biliverdin and its derivatives. The structural organization and biophysical properties of biliverdin molecules in ordered molecular assemblies might be different from those in organic solvents, but similar to those in biological membranes in mammals. Therefore, biliverdin or its derivatives incorporated in ordered molecular fil… 相似文献
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