Effect of Small-molecule Sensitizer on the Performance of Polymer Solar Cell

For improving optical absorption of organic solar cells, a small-molecule sensitizer, as a third material, is usually incorporated into binary solar cell system. In many cases, light harvesting can be improved but on the expense of charge carrier mobility of the solar cells. This obstacle can be addressed through the understanding solar cell physics. In the present work, we try to deeply understand the physics of the long-chain polymer solar cell composed of poly(3-hexylthiophene) (P3HT), as a donor polymer, and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), as an acceptor molecule. This understanding can be acquired through the effect of coumarin 6 dye (C6), as a small-molecule sensitizer, on optical absorption and photocurrent of the most common solar cell. From optical spectroscopy we found that, the C6 dye, as a small molecule, did not vary conjugation length of the long-chain polymer in the P3HT: PCBM: C6 solar cell. This was indicated from (1) unchanged vibronic structure of the P3HT after adding C6 dye and from (2) matching in the wavelength between absorption peaks of both pristine C6 and P3HT after adding C6 dye into blend. From photocurrent spectroscopy we found that, the incorporation of C6 dye, as a sensitizer, into P3HT: PCBM binary contributed to photocurrent and formed an additional charge carrier generation site through the C6: PCBM combination, which was individually found among with P3HT: PCBM combination in the same solar cell. In the same time, the C6 dye, as a shortchain molecule, restricted the transport of charge carriers generated by P3HT as a result of low hole mobility of the C6 short-chain molecules. Through the present study, the incorporation of a small-molecule sensitizer into polymer solar cell may acquire better understanding for the performance of the most common P3HT: PCBM solar cell.Keywords: Polymer Solar Cells; Device Physics; P3HT: PCBM Solar Cell

Effect of Small-molecule Sensitizer on the Performance of Polymer Solar Cell

For improving optical absorption of organic solar cells, a small-molecule sensitizer, as a third material, is usually incorporated into binary solar cell system. In many cases, light harvesting can be improved but on the expense of charge carrier mobility of the solar cells. This obstacle can be addressed through the understanding solar cell physics. In the present work, we try to deeply understand the physics of the long-chain polymer solar cell composed of poly(3-hexylthiophene) (P3HT), as a donor polymer, and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), as an acceptor molecule. This understanding can be acquired through the effect of coumarin 6 dye (C6), as a small-molecule sensitizer, on optical absorption and photocurrent of the most common solar cell. From optical spectroscopy we found that, the C6 dye, as a small molecule, did not vary conjugation length of the long-chain polymer in the P3HT: PCBM: C6 solar cell. This was indicated from (1) unchanged vibronic structure of the P3HT after adding C6 dye and from (2) matching in the wavelength between absorption peaks of both pristine C6 and P3HT after adding C6 dye into blend. From photocurrent spectroscopy we found that, the incorporation of C6 dye, as a sensitizer, into P3HT: PCBM binary contributed to photocurrent and formed an additional charge carrier generation site through the C6: PCBM combination, which was individually found among with P3HT: PCBM combination in the same solar cell. In the same time, the C6 dye, as a short chain molecule, restricted the transport of charge carriers generated by P3HT as a result of low hole mobility of the C6 short-chain molecules. Through the present study, the incorporation of a small-molecule sensitizer into polymer solar cell may acquire better understanding for the performance of the most common P3HT: PCBM solar cell

Free Fermion and Seiberg-Witten Differential in Random Plane Partitions

A model of random plane partitions which describes five-dimensional $\mathcal{N}=1$ supersymmetric SU(N) Yang-Mills is studied. We compute the wave functions of fermions in this statistical model and investigate their thermodynamic limits or the semi-classical behaviors. These become of the WKB type at the thermodynamic limit. When the fermions are located at the main diagonal of the plane partition, their semi-classical wave functions are obtained in a universal form. We further show that by taking the four-dimensional limit the semi-classical wave functions turn to live on the Seiberg-Witten curve and that the classical action becomes precisely the integral of the Seiberg-Witten differential. When the fermions are located away from the main diagonal, the semi-classical wave functions depend on another continuous parameter. It is argued that they are related with the wave functions at the main diagonal by the renormalization group flow of the underlying gauge theory.Comment: 32 pages, 3 figures, typos correcte

A system of difference equations with elliptic coefficients and Bethe vectors

An elliptic analogue of the $q$ deformed Knizhnik-Zamolodchikov equations is introduced. A solution is given in the form of a Jackson-type integral of Bethe vectors of the XYZ-type spin chains.Comment: 20 pages, AMS-LaTeX ver.1.1 (amssymb), 15 figures in LaTeX picture environment

Enhanced initial cell responses to chemically modified anodized titanium.

BACKGROUND: Previously, we reported that anodized porous titanium implants have photocatalytic hydrophilicity. However, this effect was not always sufficient for the significant improvement of bone apposition. PURPOSE: The purpose of this study was to improve the photocatalytic properties of porous titanium implants by the fluoride modification of the anodized titanium dioxide (TiO(2)), and to investigate the initial cell response to it. MATERIALS AND METHODS: The ideal concentration of ammonium hydrogen fluoride (NH(4)F-HF(2)) used in this study was determined by a static water contact angle assay. The ideal concentration of NH(4)F-HF(2) was 0.175%, and experimental disks were treated with this concentration. A pluripotent mesenchymal cell line, C2C12, was cultured on the disks in order to investigate cell attachment, morphology, and proliferation. RESULTS: Cell attachment after 30 minutes of culturing was significantly higher for the ultraviolet-irradiated, fluoride-modified anodized TiO(2) (p < .05), and the simultaneous scanning electron microscope observation showed a rather flattened and extended cell morphology. The proliferation rate after 24 hours was also significantly higher for the fluoride-modified anodized TiO(2). CONCLUSION: Fluoride chemical modification enhances the hydrophilic property of the anodized TiO(2) and improves the initial cell response to it

Gravitational Quantum Foam and Supersymmetric Gauge Theories

We study K\"{a}hler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over \mathbb{P}^1. With such a regularization prescription, the number of the gravitational quanta becomes finite and turns to be the perturbative prepotential for five-dimensional \mathcal{N}=1 supersymmetric SU(N) Yang-Mills. These quanta are labelled by lattice points in a certain convex polyhedron on \mathbb{R}^3. The polyhedron becomes obtainable from a plane partition which is the ground state of a statistical model of random plane partition that describes the exact partition function for the gauge theory. Each gravitational quantum of the local geometry is shown to consist of N unit cubes of plane partitions.Comment: 43 pages, 12 figures: V2 typos correcte

Foxp2 Regulates Identities and Projection Patterns of Thalamic Nuclei during Development

The molecular mechanisms underlying the formation of the thalamus during development have been investigated intensively. Although transcription factors distinguishing the thalamic primordium from adjacent brain structures have been uncovered, those involved in patterning inside the thalamus are largely unclear. Here, we show that Foxp2, a member of the forkhead transcription factor family, regulates thalamic patterning during development. We found a graded expression pattern of Foxp2 in the thalamic primordium of the mouse embryo. The expression levels of Foxp2 were high in the posterior region and low in the anterior region of the thalamic primordium. In Foxp2 (R552H) knockin mice, which have a missense loss-of-function mutation in the forkhead domain of Foxp2, thalamic nuclei of the posterior region of the thalamus were shrunken, while those of the intermediate region were expanded. Consistently, Foxp2 (R552H) knockin mice showed changes in thalamocortical projection patterns. Our results uncovered important roles of Foxp2 in thalamic patterning and thalamocortical projections during development. © 2017 Author.Embargo Period 12 month

Particle velocity in noncommutative space-time

We investigate a particle velocity in the $\kappa$-Minkowski space-time, which is one of the realization of a noncommutative space-time. We emphasize that arrival time analyses by high-energy $\gamma$-rays or neutrinos, which have been considered as powerful tools to restrict the violation of Lorentz invariance, are not effective to detect space-time noncommutativity. In contrast with these examples, we point out a possibility that {\it low-energy massive particles} play an important role to detect it.Comment: 16 pages, corrected some mistake