カイカン ジュウゴウホウ ニ ヨル コウイチ センタクテキ メチルカ セルロース ノ カガク ゴウセイ ト ソノ ヨウエキ ブッセイ

京都大学0048新制・課程博士博士(農学)甲第10258号農博第1330号新制||農||867(附属図書館)学位論文||H15||N3779(農学部図書室)UT51-2003-H679京都大学大学院農学研究科森林科学専攻(主査)教授 中坪 文明, 教授 松本 孝芳, 教授 西尾 嘉之学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

有機半導体のp型・n型極性と末端分子構造の相関

本研究では、末端分子構造のわずかな違いにより、発現する極性が変化することが見出された。有機半導体は、p型、n型、両極性のそれぞれの特性が末端構造に関係する事を示唆するもので、電極に依存しない極性変化を示す。This study reveal the relationship between molecular terminal structure and semiconductor polarity on organic field-effect transistors. p-, n-, or ambipolar Semiconducting properties are selected by the design of molecular structure of terminal units.研究課題/領域番号:23750216, 研究期間(年度):2011-201

金属酸化物のアモルファス化による機能発現

金沢大学ナノマテリアル研究所 / 大阪大学本研究では金属酸化物系薄膜において、アモルファス化による電子物性制御と、デバイスにおいてそれが有益に機能し得ることを実証することを目的としている。ジルコニアに続いて、ハフニアの薄膜でも、ｎ型半導体として機能している実験結果が得られた。ハフニアの性能が良好であった事をうけて、混合系を検討した。いずれの場合も、単一系よりもさらに良好な物性が得られた。この結果は、アモルファス酸化物の可能性を示すものであり、混合系における準位創出、利用がうまく機能したものと考えている。This research focused on the amorphous metal oxide application as an n-type semiconductor. Zirconia, hafunia and these mixed system were well worked in the organic photovoltaic cell as an n-type semiconductor. The results revealed that amorphous metal oxides have high potential for utilizing as the semiconductor.研究課題/領域番号:15K13772, 研究期間(年度):2015-04-01 - 2017-03-3

Interfacial Reaction of Fulleropyrrolidines Affecting Organic Photovoltaic Performance

Fulleropyrrolidine derivatives are intrinsically basic owing to the amino group within the pyrrolidine structure. It can be predicted that the basicity of fulleropyrrolidine may affect the photovoltaic devices containing an acidic layer (e.g., PEDOT:PSS). To clarify the effect of basic fulleropyrrolidine derivatives, we synthesized compounds with an <i>N</i>-benzyl substituent group and fabricated organic photovoltaic (OPV) cells using this <i>N</i>-benzyl fulleropyrrolidine. A device structure with the ITO/PEDOT:PSS/organic layer (PTB7:fulleropyrrolidine)/Ca/Al showed high series resistance, short-circuit current density (<i>J</i>_sc), and low fill factor (FF) values. However, OPV cells having an inverted structure, without the PEDOT:PSS layer, contributed good device performance. We were able to reproduce the high series resistance in a model experiment using aqueous ammonia vapor to treat the PEDOT:PSS layer. Our results indicated that the activity of the PEDOT:PSS layer was affected by the basicity of the fulleropyrrolidines. These results also explain why this phenomenon does not occur at the interface of OPV devices when conventional [6,6]-phenyl C₆₁ butyric acid methyl ester is used as an acceptor material. This finding would contribute to enhancing the OPV device performances from a chemical view point of designing a new compound

Pyradinodithiazole: An Electron-Accepting Monomer Unit for Hole-Transporting and Electron-Transporting Conjugated Copolymers

Pyradinodithiazole (<b>PDTz</b>) was designed as a new electron-accepting unit. The physical property measurements indicated that the <b>PDTz</b> unit has stronger electron-accepting characteristics than thiazolothiazole and benzodithiazole. A donor–acceptor copolymer containing <b>PDTz</b> as an acceptor unit was synthesized for hole-transporting semiconductors in organic photovoltaics (OPV). Furthermore, an acceptor–acceptor copolymer containing <b>PDTz</b> has also been developed for electron-transporting OPV materials. These copolymer-based blend films showed expected photovoltaic characteristics in individual OPV devices

Low-Temperature Processed TiOx Electron Transport Layer for Efficient Planar Perovskite Solar Cells

The most frequently used n-type electron transport layer (ETL) in high-efficiency perovskite solar cells (PSCs) is based on titanium oxide (TiO2) films, involving a high-temperature sintering (&gt;450 &deg;C) process. In this work, a dense, uniform, and pinhole-free compact titanium dioxide (TiOx) film was prepared via a facile chemical bath deposition process at a low temperature (80 &deg;C), and was applied as a high-quality ETL for efficient planar PSCs. We tested and compared as-deposited substrates sintered at low temperatures (&lt; 150 &deg;C) and high temperatures (&gt; 450 &deg;C), as well as their corresponding photovoltaic properties. PSCs with a high-temperature treated TiO2 compact layer (CL) exhibited power conversion efficiencies (PCEs) as high as 15.50%, which was close to those of PSCs with low-temperature treated TiOx (14.51%). This indicates that low-temperature treated TiOx can be a potential ETL candidate for planar PSCs. In summary, this work reports on the fabrication of low-temperature processed PSCs, and can be of interest for the design and fabrication of future low-cost and flexible solar modules

Synthesis, Properties, and Photovoltaic Performances of Donor–Acceptor Copolymers Having Dioxocycloalkene-Annelated Thiophenes As Acceptor Monomer Units

New donor–acceptor-type copolymers containing dioxocycloalkene-annelated thiophenes as electron-accepting units have been designed and synthesized for application to p-type organic semiconducting materials in organic photovoltaics. The investigation of their photophysical and electrochemical properties revealed that these copolymers possessed low optical bandgaps (from 1.63 to 1.92 eV) and low-lying HOMO energy levels (from −5.41 to −5.33 eV). Organic field-effect transistor measurements revealed that these copolymers had hole-transporting characteristics with mobilities on the order of 10^–7–10^–4 cm² V^–1 s^–1. The bulk-heterojunction photovoltaic devices fabricated from blends of these copolymers with fullerene derivatives as acceptors showed high power conversion efficiencies of up to 4.87%, with an open-circuit voltage of 0.90 V, a short-circuit current of 11.46 mA cm^–2, and a fill factor of 0.48 under air mass 1.5 simulated solar illumination

Enhanced Photovoltaic Performance of Amorphous Copolymers Based on Dithienosilole and Dioxocycloalkene-annelated Thiophene

Organic photovoltaics (OPVs) have attracted considerable attention due to their potential for generating renewable energy. The power conversion efficiency (PCE) of the OPVs largely depends on the organic semiconducting materials. Thus, the elucidation of structure–property OPV performance relationships is important for the rational improvement of OPVs. Here, low-bandgap copolymers comprising dithieno­[3,2-<i>b</i>:2′,3′-<i>d</i>]­silole as a donor unit and dialkyl-substituted naphtho­[2,3-<i>c</i>]­thiophene-4,9-dione as an acceptor unit were synthesized to investigate the influence of the polymer molecular weight and the alkyl chain length in the acceptor unit on the polymer properties and photovoltaic performance. All the prepared copolymers are amorphous in the solid state. Both the increase of polymer molecular weight and variation of the alkyl side chains in the acceptor unit subtly affected molecular properties. However, these structural modifications showed significant impact on the photovoltaic performance in bulk heterojunction (BHJ) solar cells based on copolymer/[6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM), with PCEs that range between 2.35 and 5.21%. Furthermore, the optimization of thin-film fabrication by use of a ternary solvent system led to the appearance of improved morphology accompanied by subtly ordered states of the copolymer in the BHJ films and, hence, improved carrier mobility and charge-separation efficiency. Consequently, the BHJ solar cell can achieve a PCE of 7.85%, which is the highest performance among the amorphous copolymers in the conventional device structure. This result highlights the importance of fine-tuning both the molecular structure and device fabrication in the construction of high-performance organic photovoltaics based on amorphous copolymers and PC₇₁BM