京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19002号 / 工博第4044号 / 新制||工||1622(附属図書館) / 31953 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 白川 昌宏, 教授 田中 庸裕, 教授 濵地 格 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The sensitivity of biological studies performed between 190 and 650 nm is greatly reduced due to the autofluorescence of biomolecules and impurities in this region. Therefore, the enhanced signal-to-noise ratios encountered at longer wavelengths makes biological analysis within the near infrared (NIR) region from 650 nm to 1100 nm far more advantageous. This dissertation describes the noncovalent binding interactions of near-infrared (NIR) carbocyanine dyes with human serum albumin (HSA) and poly-L-lysine (PLL) using UV-Vis/NIR absorption spectroscopy, emission spectroscopy, circular dichroism (CD), and fluorescence detected circular dichroism (FDCD). The optical spectroscopy methods used in this work are described in detail in Chapter 1. The various applications of NIR dyes in protein analysis are introduced in Chapter 2. In general, the sensitivity of cyanines to the polarity of their local environment makes them quite suitable for protein labeling schemes. In aqueous media, cyanines have a high propensity for self-association. Yet in the hydrophobic binding sites of globular proteins, these aggregates often dissipate. Absorption and emission spectroscopy can be utilized to observe the differential spectral properties of monomer, intra-molecular and intermolecular aggregates. In Chapter 3, the photophysical properties of bis(cyanine) NIR dyes containing di-, tri-, and tetraethylene glycol linkers were each examined in the presence of HSA are discussed. Variations in chain length as well as probe flexibility were demonstrated through distinct differences in absorption and emission spectra. The observed changes in the spectral properties of the NIR dyes in the presence and absence of HSA were correlated to the physical parameters of the probes' local environment (i.e., protein binding sites and self-association). All three bis-cyanines examined exhibited enhanced fluorescence in the presence of HSA. The bis-cyanine dye containing the tri(ethylene glycol) spacer allowed for a complete overlap of the benzene rings, to form π-π interactions which were observed as intra-molecular H-aggregate bands. The dye exhibited no fluorescence in buffer, owing to the H-aggregation observed in the absorption data. In the presence of HSA, the intra-molecular dimers were disrupted and fluorescence was then detected. The "cut-on" fluorescence displayed by the dye in the presence of HSA made it ideal for noncovalent labeling applications. The utility of several NIR dyes for use as secondary structural probes was investigated in Chapter 4. NIR dyes were screened thoroughly using UV-Vis/NIR absorption spectroscopy dyes with spectral properties which were sensitive to protein secondary structure models of such as PLL in basic solution. Two NIR dyes were found to be quite sensitive to the structural features of uncharged α- and β-PLL. The chiral discrimination of these probes for basic protein secondary structures was also evaluated through CD measurements within the NIR probes' absorption bands.

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O objetivo deste trabalho foi de estudar processos de transporte eletrônico em dispositivos a base de semicondutores orgânicos através de técnicas avançadas, como ressonância magnética detectada eletricamente (RMDE) e espectroscopia de impedância elétrica em corrente alternada. Além destas, medidas de ressonância paramagnética eletrônica (RPE) convencional também foram realizadas de forma a complementar as medidas de RMDE. Os dispositivos e materiais estudados foram: (hole-only e PLED) de MEH-PPV, polianilina e OLED multicamadas de Alq3 e -NPD. A técnica de RMDE mede a variação de condutividade da amostra na condição de ressonância magnética, permitindo relacionar processos microscópicos com os seus efeitos nos processos de transporte eletrônico. Os estudos de RPE e RMDE em polianilina mostraram uma transição entre os tipos de spin observados em função da temperatura. Os resultados obtidos indicam que o sinal de RPE se deve principalmente a estados de superfície, enquanto a técnica de RMDE permite observarmos também estados do volume, dependendo da forma de preparação dos dispositivos e dos parâmetros utilizados nas medidas. O sinal de RMDE foi atribuído ao hopping de pólarons intercadeias poliméricas. Nos dispositivos de MEH-PPV, o sinal de RMDE apresenta duas componentes, uma foi atribuída à fusão de pólarons negativos para formar bipólarons negativos e a outra foi atribuída à fusão de pólarons positivos. A deficiência na emissão de luz de alguns dos PLEDs estudados foi atribuída ao desbalanceamento de injeção de cargas, que pode ser observado pela diferença de intensidade entre as componentes do sinal. Nos OLEDs a base de Alq3, medidas de espectroscopia de impedância elétrica em função da voltagem dc (Vdc) mostraram um acúmulo de cargas nas interfaces internas do dispositivo, em baixas tensões. Entretanto, para valores mais altos de Vdc, quando começa o processo de recombinação, foi observado um fenômeno pouco estudado na literatura, conhecido como capacitância negativa. Possíveis abordagens a este problema foram propostas / The subject of this work is the investigation of electronic transport processes in organic semiconductors based devices using advanced techniques, such as electrically detected magnetic resonance (EDMR) and ac electrical impedance spectroscopy. Electron Paramagnetic Resonance (EPR) measurements were also carried out to complement the EDMR results. The studied devices and materials were: MEH-PPV hole-only devices and PLEDs, polyaniline and multilayer Alq3 and -NPD based OLEDs. EDMR measures the sample conductivity variation during magnetic resonance condition, which allows relating microscopic processes to its effects on electronic transport processes. EPR and EDMR investigations on polyaniline showed a transition between two kinds of observed spins as a function of temperature. The results indicate that EPR probes especially surface paramagnetic states, while EDMR allows observing both surface and bulk paramagnetic states, depending on how devices are prepared and on some measurement parameters. The EDMR signal was assigned to interchain hopping of pólarons. On MEH-PPV devices, the EDMR signal was composed of two lines, one was attributed to negative pólarons fusion to form negative bipólarons and the other was assigned to positive pólarons fusion. The light emitting deficiency presented by some of the PLEDs investigated was assigned to a misbalanced charge injection, what could be observed by the difference between the intensity of the two components. Impedance spectroscopy measurements on Alq3 based OLEDs as a function of the dc voltage (Vdc) showed charge accumulation at the inner interfaces of the device at low Vdc values. However, at higher Vdc values, when recombination starts to take place, a strange phenomenon, usually called negative capacitance, was observed. Possible approaches were proposed

This thesis work aims at a better understanding of magneto-optical properties of dilute nitrides and II-VI diluted magnetic semiconductor quantum structures. The thesis is divided into two parts. The first part gives an introduction of the research fields, together with a brief summary of the scientific results included in the thesis. The second part consists of seven scientific articles that present the main findings of the thesis work. Below is a short summary of the thesis. Dilute nitrides have been of great scientific interest since their development in the early 1990s, because of their unusual fundamental physical properties as well as their potential for device applications. Incorporation of a small amount of N in conventional Ga(In)As or Ga(In)P semiconductors leads to dramatic modifications in both electronic and optical properties of the materials. This makes the dilute nitrides ideally suited for novel optoelectronic devices such as light emitting devices for fiber-optic communications, highly efficient visible light emitting devices, multi-junction solar cells, etc. In addition, diluted nitrides open a window for combining Si-based electronics with III-V compounds-based optoelectronics on Si wafers, promising for novel optoelectronic integrated circuits. Full exploration and optimization of this new material system in device applications requires a detailed understanding of their physical properties. Papers I and II report detailed studies of effects of post-growth rapid thermal annealing (RTA) and growth conditions (i.e. presence of N ions, N2 flow, growth temperature and In alloying) on the formation of grown-in defects in Ga(In)NP. High N2 flow and bombardment of impinging N ions on grown sample surface is found to facilitate formation of defects, such as Ga interstitial (Gai) related defects, revealed by optically detected magnetic resonance (ODMR). These defects act as competing carrier recombination centers, which efficiently decrease photoluminescence (PL) intensity. Incorporation of a small amount of In (e.g. 5.1%) in GaNP seems to play a minor role in the formation of the defects. In GaInNP with 45% of In, on the other hand, the defects were found to be abundant. Effect of RTA on the defects is found to depend on initial configurations of Gai related defects formed during the growth. In Paper III, the first identification of an interfacial defect at a heterojunction between two semiconductors (i.e. GaP/GaNP) is presented. The interface nature of the defect is clearly manifested by the observation of ODMR lines originating from only two out of four equivalent <111> orientations. Based on its resolved hyperfine interaction between an unpaired electronic spin (S=1/2) and a nuclear spin (I=1/2), the defect is concluded to involve a P atom at its core with a defect/impurity partner along a <111> direction. Defect formation is shown to be facilitated by N ion bombardment. In Paper IV, the effects of post-growth hydrogenation on the efficiency of the nonradiative (NR) recombination centers in GaNP are studied. Based on the ODMR results, incorporation of H is found to increase the efficiency of the NR recombination via defects such as Ga interstitials. In Paper V, we report on our results from a systematic study of layered structures containing an InGaNAs/GaAs quantum well, by the optically detected cyclotron resonance (ODCR) technique. By monitoring PL emissions from various layers, the predominant ODCR peak is shown to be related to electrons in GaAs/AlAs superlattices. This demonstrates the role of the SL as an escape route for the carriers confined within the InGaNAs/GaAs single quantum well. The last two papers are within a relatively new field of spintronics which utilizes not only the charge (as in conventional electronics) but also the quantum mechanical property of spin of the electron. Spintronics offers a pathway towards integration of information storage, processing and communications into a single technology. Spintronics also promises advantages over conventional charge-based electronics since spin can be manipulated on a much shorter time scale and at lower cost of energy. Success of semiconductor-based spintronics relies on our ability to inject spin polarized electrons or holes into semiconductors, spin transport with minimum loss and reliable spin detection. In Papers VI and VII, we study the efficiency and mechanism for carrier/exciton and spin injection from a diluted magnetic semiconductor (DMS) ZnMnSe quantum well into nonmagnetic CdSe quantum dots (QD’s) by means of spin-polarized magneto PL combined with tunable laser spectroscopy. By means of a detailed rate equation analysis presented in Paper VI, the injected spin polarization is deduced to be about 32%, decreasing from 100% before the injection. The observed spin loss is shown to occur during the spin injection process. In Paper VII, we present evidence that energy transfer is the dominant mechanism for carrier/exciton injection from the DMS to the QD’s. This is based on the fact that carrier/exciton injection efficiency is independent of the width of the ZnSe tunneling barrier inserted between the DMS and QD’s. In sharp contrast, spin injection efficiency is found to be largely suppressed in the structures with wide barriers, pointing towards increasing spin loss.

To fully exploit the capability of NV centers in diamond as magnetic sensors and quantum bits, the optimum production recipe as well as the method to enhance its optical performance has been studied in this work. The NV centers in bulk diamond were prepared by ion implantation and electron irradiation, and the optimum dose and temperature are found by comparing its optical and magnetic performance both experimentally and theoretically. In addition, the enhancement of optical performance and size characterization of NV centers in nanodiamonds will be discussed in this work.

This diploma thesis starts with the definition of terms and formulations which are necessary for the understanding the discussed issues. The diploma thesis deals with real estate income method valuation, in particular the detected value and the market value according to the relevant public notice of valuation. In the practical part of the thesis my main aim has beeen to choose the real estate that can be valued by the real estate income method, to establish the detected value according to the public notice 445/2017 Sb. and to establish the market value, which will be set with several other real estate.

O objetivo deste trabalho foi de estudar processos de transporte eletrônico em dispositivos a base de semicondutores orgânicos através de técnicas avançadas, como ressonância magnética detectada eletricamente (RMDE) e espectroscopia de impedância elétrica em corrente alternada. Além destas, medidas de ressonância paramagnética eletrônica (RPE) convencional também foram realizadas de forma a complementar as medidas de RMDE. Os dispositivos e materiais estudados foram: (hole-only e PLED) de MEH-PPV, polianilina e OLED multicamadas de Alq3 e -NPD. A técnica de RMDE mede a variação de condutividade da amostra na condição de ressonância magnética, permitindo relacionar processos microscópicos com os seus efeitos nos processos de transporte eletrônico. Os estudos de RPE e RMDE em polianilina mostraram uma transição entre os tipos de spin observados em função da temperatura. Os resultados obtidos indicam que o sinal de RPE se deve principalmente a estados de superfície, enquanto a técnica de RMDE permite observarmos também estados do volume, dependendo da forma de preparação dos dispositivos e dos parâmetros utilizados nas medidas. O sinal de RMDE foi atribuído ao hopping de pólarons intercadeias poliméricas. Nos dispositivos de MEH-PPV, o sinal de RMDE apresenta duas componentes, uma foi atribuída à fusão de pólarons negativos para formar bipólarons negativos e a outra foi atribuída à fusão de pólarons positivos. A deficiência na emissão de luz de alguns dos PLEDs estudados foi atribuída ao desbalanceamento de injeção de cargas, que pode ser observado pela diferença de intensidade entre as componentes do sinal. Nos OLEDs a base de Alq3, medidas de espectroscopia de impedância elétrica em função da voltagem dc (Vdc) mostraram um acúmulo de cargas nas interfaces internas do dispositivo, em baixas tensões. Entretanto, para valores mais altos de Vdc, quando começa o processo de recombinação, foi observado um fenômeno pouco estudado na literatura, conhecido como capacitância negativa. Possíveis abordagens a este problema foram propostas / The subject of this work is the investigation of electronic transport processes in organic semiconductors based devices using advanced techniques, such as electrically detected magnetic resonance (EDMR) and ac electrical impedance spectroscopy. Electron Paramagnetic Resonance (EPR) measurements were also carried out to complement the EDMR results. The studied devices and materials were: MEH-PPV hole-only devices and PLEDs, polyaniline and multilayer Alq3 and -NPD based OLEDs. EDMR measures the sample conductivity variation during magnetic resonance condition, which allows relating microscopic processes to its effects on electronic transport processes. EPR and EDMR investigations on polyaniline showed a transition between two kinds of observed spins as a function of temperature. The results indicate that EPR probes especially surface paramagnetic states, while EDMR allows observing both surface and bulk paramagnetic states, depending on how devices are prepared and on some measurement parameters. The EDMR signal was assigned to interchain hopping of pólarons. On MEH-PPV devices, the EDMR signal was composed of two lines, one was attributed to negative pólarons fusion to form negative bipólarons and the other was assigned to positive pólarons fusion. The light emitting deficiency presented by some of the PLEDs investigated was assigned to a misbalanced charge injection, what could be observed by the difference between the intensity of the two components. Impedance spectroscopy measurements on Alq3 based OLEDs as a function of the dc voltage (Vdc) showed charge accumulation at the inner interfaces of the device at low Vdc values. However, at higher Vdc values, when recombination starts to take place, a strange phenomenon, usually called negative capacitance, was observed. Possible approaches were proposed

Táto diplomová práca sa venuje vylepšeniu spektroskopu Torzne Detegovanej Elektrónovej Spinovej Rezonancie (TDESR) výmenou aktuálnej kapacitnej detekcie výchylky ohybného ramienka za optické metódy. Práca popisuje základy Elektrónovej Spinovej Rezonančnej (ESR) spektroskopie s dôrazom na TDESR a tému magnetizmu jednomolekulových magnetov. Následne je vysvetlená detekcia výchylky ramienka pomocou odrazu laserového zväzku a interferometrie. Všetky kroky nutné k skonštruovaniu spektrometra a jeho uvedenia do prevádzky sú podrobne popísané. Pomocou detekcie odrazu laserového zväzku sme úspešne získali vysoko kvalitné TDESR spektrá kryštálu jednomolekulového magnetu Fe4. Týmto meraním sme dokázali vhodnosť použitia tejto metódy a jej výraznú prevahu nad pôvodnou kapacitnou detekciou, najmä v oblasti kvality, rozlíšenia a rýchlosti. Zároveň sme na ďaľšie vylepšenie TDESR spektrometra navrhli a zostrojili zostavu využívajúcu na detekciu výchylky interferometer.

Using shallow implantation of ions and molecules with masses centred at 27 atomic mass units(amu) in diamond, a new artificial optical centre with unique properties has been created. The centre shows a linearly polarised fluorescence with a main narrow emission line mostly found at 582 nm, together with a weak vibronic sideband at room temperature. The fluorescence lifetime is∼2 ns and the brightest centres are more than three times brighter than the nitrogen-vacancy centres. A majority of the centres shows stable fluorescence whereas some others present a blinking behaviour, at faster or slower rates. Furthermore, a second kind of optical centre has been simultaneously created in the same diamond sample, within the same ion implantation run. This centre has a narrow zero-phonon line (ZPL) at∼546 nm and a broad phonon sideband at room temperature. Interestingly, optically detected magnetic resonance (ODMR) has been measured on several single 546 nm centres and two resonance peaks are found at 0.99 and 1.27 GHz. In view of their very similar ODMR and optical spectra, the 546 nm centre is likely to coincide with the ST1 centre, reported once (with a ZPL at 550 nm), but of still unknown nature. These new kinds of centres are promising for quantum information processing, sub-diffraction optical imaging or use as single-photon sources.