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

A Study on the Expropriation Behavior of Controlling Shareholders of China’s Listed Companies

传统的公司治理理论研究的是在贝利-米恩斯式的公司中解决股东与经理层之间的利益冲突，设计一种激励约束兼容的制衡机制使得经理层的行为符合公司及股东利益最大化的要求。但是20世纪80年代，学者们发现相对集中或高度集中的股权结构是许多国家上市公司的主要特征，公司治理的主要矛盾已经转变为控制性股东与中小股东之间的利益冲突。我国上市公司控制性股东通过控制股东大会及董事会进而侵害中小股东及上市公司利益的事例时有发生，并日益受到广泛的关注。因此，弄清控制权这一具有巨大价值的权力在公司治理中所起到的作用，设计一种制衡控制性股东利益的制度，与解决所有权与经营权的委托代理关系同等重要。这是完善公司治理，建立现代企业...The principal-agent relation between managements and shareholders used to be the focus of the study on corporate governance in those companies whose ownership were dispersive.However,the results of some newly research show that most listed companies’ ownership structures are relatively concentrative in many countries over the world, which results in interest conflict between the controlling shareh...学位：经济学硕士院系专业：经济学院经济系_经济思想史学号：1532006115078

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

Management of Lacerated and Swollen Tongue after Convulsive Seizure with a Mouth Protector: Interprofessional Collaboration Including Dentists in Intensive Care

We encountered a 74-year-old male patient with tongue laceration after convulsive seizures under intensive care. The tongue showed severe swelling, and the right ventral surface had been lacerated by his isolated and pointed right lower canine. Our university hospital has established a perioperative management center, and is promoting interprofessional collaboration, including dentists, in perioperative management. Dentists collaborating in the perioperative management center took dental impressions, with the support of anesthesiologists who opened the patientʼs jaw under propofol sedation, to produce a mouth protector. By raising the patientʼs bite, the completed mouth protector prevented the isolated tooth from contacting the tongue and protected the lacerated wound. Use of the mouth protector prevented the lacerated tongue from coming into contact with the pointed tooth, and the tongue healed gradually. These findings underscore that interprofessional collaboration including dentists can improve the quality of medical care

Poly[(3-hexylthiophene)-block-(3-semifluoroalkylthiophene)] for Polymer Solar Cells

We report the synthesis of poly[(3-hexylthiophene)-block-(3-(4,4,5,5,6,6,7,7,7-nonafluoroheptyl)thiophene)], P(3HT-b-3SFT), carried out by the Grignard Metathesis Method (GRIM). The copolymers composition was determined by 1H and 19F NMR spectroscopies, and gel permeation chromatography (GPC). The thin films of P(3HT-b-3SFT) were investigated by ultraviolet-visible absorption spectroscopy and atomic force microscopy (AFM). We also fabricated bulk-hetero junction (BHJ) solar cells based on blends of P(3HT-b-3SFT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Although the composition ratio of P3SFT in P(3HT-b-3SFT) was low, the influence of P3SFT on the morphology and properties of solar cells was significant. The annealing process for the BHJ solar cells induced the formation of large domains and led to poor solar cell performance. The BHJ solar cells, based on PCBM and P(3HT-b-3SFT), prepared by the non-annealing process, had a maximum power conversion efficiency of 0.84% under 100 mW/cm2 (AM 1.5 solar illumination) in air

Functionalized graphene-based nanocomposites for smart optoelectronic applications

The recent increase in the use of graphene and its derivatives is due to their exceptional physicochemical, electrical, mechanical, and thermal properties as the industrial materials developed by involving graphene structures can fulfill future needs. In that view, the potential use of these graphene-containing nanomaterials in electronics applications has encouraged in-depth exploration of the electronic, conducting, and other functional properties. The protecting undifferentiated form of graphene has similarly been proposed for various applications, for example, as supercapacitors, photovoltaic and transparent conductors, touch screen points, optical limiters, optical frequency converters, and terahertz devices. The hybrid composite nanomaterials that undergo stimulus-induced optical and electrical changes are important for many new technologies based on switchable devices. As a two-dimensional smart electronic material, graphene has received widespread attention, and with that view, we aim to cover the various types of graphene oxide (GO)-based composites, linking their optical and electrical properties with their structural and morphological ones. We believe that the topics covered in this review can shed light on the development of high-yield GO-containing electronic materials, which can be fabricated as the field moves forward and makes more significant advances in smart optoelectronic devices

Effect of Sulfur Concentration on the Morphology of Carbon Nanofibers Produced from a Botanical Hydrocarbon

Carbon nanofibers (CNF) with diameters of 20–130 nm with different morphologies were obtained from a botanical hydrocarbon: Turpentine oil, using ferrocene as catalyst source and sulfur as a promoter by simple spray pyrolysis method at 1,000 °C. The influence of sulfur concentration on the morphology of the carbon nanofibers was investigated. SEM, TEM, Raman, TGA/DTA, and BET surface area were employed to characterize the as-prepared samples. TEM analysis confirms that as-prepared CNFs have a very sharp tip, bamboo shape, open end, hemispherical cap, pipe like morphology, and metal particle trapped inside the wide hollow core. It is observed that sulfur plays an important role to promote or inhibit the CNF growth. Addition of sulfur to the solution of ferrocene and turpentine oil mixture was found to be very effective in promoting the growth of CNF. Without addition of sulfur, carbonaceous product was very less and mainly soot was formed. At high concentration of sulfur inhibit the growth of CNFs. Hence the yield of CNFs was optimized for a given sulfur concentration

Cyclodextrin-functionalized carbon nanotubes for mixed matrix membrane

Carbon nanotubes (CNTs) have generated great interest within the many areas of nanotechnology due to their superior and outstanding physical properties. However effective dispersion in many solvents has imposed limitations upon the use of CNTs in a number of novel applications. Functionalization presents a solution for CNTs to be more soluble which make them integrate well into any organic, inorganic or biological systems. CNTs can be easily functionalized using cyclodextrin (CD) treatment. The CD modification of carbon nanotubes is both simple and effective. It requires no prolonged heating, filtration and washing which can severely damage the small diameter nanotubes. The formation of surface functional groups and changes of nanotubes structures of functionalized carbon nanotubes (f-CNTs) were monitored by Fourier transform infrared spectroscopy (FTIR), Thermo gravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM), respectively. From the TGA results, the amount of weight loss of the f-CNTs in varying ratios indicated the amount of CD that was functionalized. It was also noted that the FTIR spectra showed the presence of functional groups associated with CD in the f-CNTs. As a result, the cyclodextrin groups were found to be possibly adsorbed at the surface of the nanotubes walls. The f-CNTs showed substantial solubility in N-methyl-2-pyrrolidone (NMP) which helps in a better distribution of the CNTs in the mixed matrix membrane (MMM) prepared. Hence, the influence of the f-CNTs in the polymer matrix will give rise to enhanced physical properties of the MMM suitable for applications in gas separations