FREE ELECTRONIC LIBRARY - Thesis, documentation, books

Pages:     | 1 |   ...   | 22 | 23 || 25 | 26 |

«ANNUAL REPORT Riga 2012 Annual Report 2011, Institute of Solid State Physics, University of Latvia. Editor: A.Krumins. Composed matter: A.Muratova. ...»

-- [ Page 24 ] --

2) supervision of physics masters work of LU Physics and Mathematics Faculty student K. Bavrins.

–  –  –

Scientific projects of the Latvian Council of Sciences 09.1548 Physical Processes in Multilayer and Multicomponental Structures (2009-2013) 10.0032 „Development of research and technology potential for elaboration of new and nanostructured materials and related applications.” subproject „Supramolecular nanostructuring of photonic materials – theoretical modeling and experimental investigations” (2010-2013) National Research Program in Materials Science and Information Technologies IMIS (2010-2014) Project No.1, Multifunctional materials for high-tech applications in conversion of radiation energy, information recording, storage, transfer and processing ERAF projects of the activity”Support of science and research” No.2010/0308/2DP/, “Development of Polymer EO modulator prototype device” No. 2010/0252/2DP/, “Materials and its tandem structure for solar cells” (2010-2013) No. 2010/0275/2DP/ APIA/VIAA/124, „RTD for fabrication of diffractive optical elements” (2010-2013)

–  –  –

Institute of Chemistry, Academia Sinica, R.O.C., Taiwan

Main equipments:

1. Equipments for preparation of thin films:

the vacuum deposition of organic compounds and metals (Edwards 306A);

the Langmuir-Blodgett technique;

the self-assembled techniques;

the casting and spin-coating techniques (Lite Single Wafer Spin Processor, Laurell technology Corporation).

2. High vacuum setups for measuring of electrical and photoelectrical conductivity between 10 and 400K. The sample is provide by a digitally controlled voltage supply over range up to 5kV and the current is measured in range 1fA to 1mA.

3. Computer controlled corona poling systems.

4. Computer-controlled Kelvin probe setup with the temperature control up to +130ºC and measuring the surface potential in a range between –9.6 and +9.6V with the accuracy ±1mV. The diameter of vibrating gold electrode was 2mm

5. Scanning Kelvin Probe SKP5050

6. Surface Profile Measuring System Dektak 150

7. Computer-controlled SHG setup (λ=1064 nm) allows us to measure SHG (λ=532 nm) intensity as function of the fundamental power, incidence angle, fundamental and SH light polarization as well as sample surface mapping by SHG intensity. The detection threshold of equipment is 1 x 10-6 pm/V



1. Institute of Applied Chemistry, Riga Technical University (Prof. V.Kampars, Prof.


2. Latvian Institute of Organic Synthesis (Dr. E.Markava).

3. Institute of Chemical Physics, University of Latvia, (Dr. D.Erts).

4. Institute of Physical Energetics (Dr. I.Kaulach).


1. Institute of Physics (Prof. L.Valkunas, Dr. V.Gulbinas).

2. Institute of Material Science and Applied Research, Vilnius University, (Prof. S.Juršenas).

3. Kaunas Technology University (Prof. J.V. Grazulevicius) Germany

1. Lehrstuhl Physik kondensierter Materie, Universität Potsdam, Potsdam (Prof. D.Neher, Dr. B.Stiller).


1. Institute of Chemistry, Academia Sinica, (Prof. Chao-Ping Hsu)

–  –  –

Calculation of chromophore polar order, i.e. polarization, of poled by external field nonlinear optically (NLO) active polymers is challenging. One of possible solutions is to reproduce the orientation polarization of chromophores under external field using Langevin dynamics (LD) molecular modeling.

–  –  –

0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2

–  –  –

-0.6 -0.6

-0.8 -0.8

-1.0 -1.0 DC poling hysteresis loops of model clusters built from 10 D dipoles with dipole density N = 10x1020 mol/cc: a) “Guest/ Host” system; b) and “Grafted” system In spotlight of this investigation we would like to describe NLO polymer as a “coloid” mixture or “ferrofluid” were chromophores (in our case model dipolar molecules) take part in the role of active particles - electrets. According to our simulations of model systems at low dipolar densities such system behaves “paraelectric” like. For dipole densities within a range of practical interest polarization behavior of such “ferrofluid” profoundly depends on translation movement freedom of electrets and their dipole moment. In the model systems where translation movement of “electrets” is prohibited (“Grafted” models) an “antiferroelectric” behavior start to show up with increase of dipole density and moment value. In a case when “electrets” allowed moving freely (“Guest/Host”) model systems behavior is different. Dipolar “chains” and “rings” are formed with dipole density rise in “Guest/Host” model systems. The dipolar “chains” could form “ferroelectric” like structure when oriented parallel or “antiferroelectric” like if in opposite orientation and “rings” definitely behaves “antiferroelectric” like. The shape of obtained polarization hysteresis loops allows us to suggest coexistence of both “antiferroelectric” and “ferroelectric” like structures in densely loaded “Guest/Host” model systems.

The outcome of these chromophore poling simulations of model systems by Langevin Dynamics convinced us, that method could be applicable for modeling of real chromophore/polymer composites. Results obtained within an investigated model systems give us some inspirations for practical NLO polymer design. First of all our model simulations confirm that at low (typically used for NLO polymers) poling fields high dipole moment chromophores are preferable and should yield a higher load factor and therefore better NLO efficiency. In a case when one could achieve a higher poling field values low dipole moment chromophores should perform better and higher NLO efficiency achieved.

Increased (above typically used nowadays) poling fields could be a key for breakthrough in EO polymer design. Possibility to achieve same (or even higher) NLO efficiency by using low μ with high Ep scheme in contradiction to high μ with low Ep could be recommended also due to eventually better PO stability.

This research was granted by Latvian National Research Program in Materials Science, Project No.3 “Materials for photonics and nanoelectronics based on novel functional low molecular organic compounds and polymers” and Latvian Council of Science collaboration project 10.0032 „ Development of research and technology potential for elaboration of new and nanostructured materials and related applications.” subproject 10.0032.14 “Supramolecular nanostructuring of photonic materials – theoretical modeling and experimental investigations”.

–  –  –

Study of charge carrier transport in organic electroluminescent devices, organic photovoltaic devices, and organic field-effect transistors is one of the most important points. In order to realize comparable electron and hole transport in thin organic films with electrodes the energy structure of such devices are of great importance. In this work, we have studied electrical properties and energy structure of two carbazole derivatives.

–  –  –

The energy gap of two carbazole derivatives 1 and 2 in thin film is obtained. The energy gap characterisized by threshold energy of photoconductivity quantum efficiency is 2.90 eV and optical energy gap following from optical absorption spectrum is 3.3 eV for compound 1 in thin films. The values of the surface potential characterisizing ionization potential in solid state (hole conducting energy level) are 5.17 eV for compound 1 and 5.19 eV for compound

2. The values of work function of ITO, Au, Cu and Pd electrodes are energetically close to conductivity level of holes (Eh) and holes injection dominates from electrodes. In these thin films local trapping states of holes are situated at holes conducting level. When electrode is Al layer the local shallow trapping states for electrons at Et = 0.10 eV for compound 1 and at Et = 0.18 eV for compound 2 are determined This work is supported by ERAF Project Nr. 2DP/ and LatvianLithuanian-Taiwan joint project „Design, Synthesis and Studies of New Effective Materials for Organic Optoelectronics”



–  –  –

The organic light emitting diode (OLED) has a promising applications in flat panel displays and novel light sources. So far the OLED structures have mostly been made by thermal evaporation in vacuum. An alternative approach is to use small molecules which form amorphous (glassy) structure from solutions. Such compounds can be used in the ink-jet printing technologies and result in reducing the OLED prices. In this paper, we present an original red fluorescent organic compound 2-(2-(4-(bis(2-(trityloxy)ethyl)amino)styryl)-6methyl-4H-pyran-4-ylidene)-1H-indene-1,3(2H)-dione (ZWK1) and it derivative 2-(2,6-bis(4bis(2-(trityloxy)ethyl) amino)styryl)-4H-pyran-4-ylidene)-1H-indene-1,3(2H)-dione (ZWK2) where methyl group replaced with 4-substituted-styryl group. This change could improve the formation of glassy structure.

–  –  –

Electroluminescence spectrum of ZWK1 (line) and ZWK2 (doted line) The thickness of the electroluminescent layer in the device was optimized to the higher power efficiency and obtained: ITO/PEDOT:PSS(40nm)/ZWK1(95nm) /LiF(1nm)/Al(100nm) and ITO/PEDOT:PSS(40nm)/ZWK2(85nm)/LiF(1nm)/Al(100nm). The maximum of electroluminescence spectra for the device with ZWK1 compound was 667 nm wich correspond to the CIE coordinates x=0.65 and y=0.34. The power and luminance efficiency at the luminance of 100 cd/m2 is 0.63 lm/W and 1.78 cd/A, respectively. Adding additional 4substituted-styryl group to ZWK1 molecule shifted maximum of EL spectra to red region (705 nm) and decreased the efficiencies by one order.

This research was granted by Latvian National Research Program in Materials Science, Project No.3 “Materials for photonics and nanoelectronics based on novel functional low molecular organic compounds and polymers” and by the European Social Fund within the project «Support for Doctoral Studies at University of Latvia»

Scientific publications

1. A.Vembris, M.Porozovs, I.Muzikante, V.Kokars, E.Zarins, Pyranylidene indene-1,3-dione derivatives as an amorphous red electroluminescence material, Journal of Photonics for Energy, 2011, Vol.1, 011001, DOI: 10.1117/1.3524819

2. M.Indrikova, J.Latvels, I.Muzikante, B.Turovska, Photoelectrical Properties and Energetical Structure of Thin Films of Indandione Derivatives, Materials Science, 2011Vol.17, No.2, pp.125-131

3. D.Gustina, E.Markava, E.Laizane, I.Muzikante, Synthesis and investigation of photoisomerization of some new azobenzene carboxylic acids, Latvian J.Chemistry, 2011, No.1/2, pp.129–138, DOI 10.2478/v10161-011-0058-4

4. M. Rutkis, A. Jurgis, Insight in NLO polymer material behavior by Langevin dynamic modeling of chromophore poling, Integrated Ferroelectrics, 123, 2011, pp 53-65, http://dx.doi.org/10.1080/10584587.2011.570635

5. R.Grzibovskis, J.Latvels, I.Muzikante, Photoelectrical properties of thin films of DMABI derivatives, IOP Conf. Series: Materials Science and Engineering, 2011, Vol.23, 012021 doi:10.1088/1757-899X/23/1/012021

6. K.Pudzs, I.Muzikante, E.Fonavs, J.Simokaitiene, S.Grigalevicius, J.V.Grazilevicius, Energy structure of thin films of carbazole derivatives with metal electrodes, IOP Conf.

Series: Materials Science and Engineering, 2011, Vol.23, 012020 doi:10.1088/1757X/23/1/012020

7. K. Traskovskis, I. Mihailovs, A.Tokmakovs, V. Kokars, V. Kampars, M. Rutkis, Synthesis and nonlinear optical properties of novel N,N-dihydroxyethyl based molecular organic glasses using triaryl substitutes as amorphous phase formation enhancers, Proc.

SPIE 8113, 81130Z (2011); doi:10.1117/12.893381

8. A.Sternbergs, I.Muzikante, R.Dobulans, D.Millers, L.Grigorjeva, K.Smits, M.Knite, G.Sakale, Polymer nanomaterials for novel sensing systems, Springer Science and Business Media - NATO Science for Peace and Security Series – B : Physics and Biophysics, 2011

9. O.Vilitis, E.Fonavs, M.Rutkis, Chromophore poling in thin films of organic glasses. 1.

Overview of corona discharge application, Latvian Journal of Physics and Technical Sciences, 2011, No. 6, pp. 53-65; DOI: 10.2478/v10047-011-0038-1


27th Scientific Conference of the Institute of Solid State Physics, University of Latvia, February 14-16, 2011

30. K.Pudžs, A.Vembris, I.Muzikante, J.V.Grazulevicius, Energy structure of thin film with carbazole derivatves determination in light emitting diode structure, Book of Abstracts, p.88

31. A.Vembris, I.Muzikante, R.Karpiz, V.Gulbinas, Red apmlified spontaneous emission in original; organic compounds, Book of Abstracts, p.89

32. M.Rutkis, I.Mihailovs, A.Tokmakovs, A.Ernstsons, Hyper-Rayleigh scattering measrements of molecular hyperpolarizability – comparison of internal and external standard methods, Book of Abstracts, p.90

33. E.Laizāne, D.Gustiņa, I.Muzikante, A.Vembris, Optical study of thin solid films with azobenzene molecules containing carboxyl groups, Book of Abstracts, p.60

34. E.Nitišs, E.Titavs, M.Rutkis, O.Vilītis, Current – voltage characteristics of corona triode setup for NLO polymer poling, Book of Abstracts, p.61

35. E.Nitišs, M.Rutkis, M.Svilans, Application of Abes matrix formalism for determination of thin organic film EO coefficients by Mach – Zehnder interferometer, Book of Abstracts, p.62 54th Scientific conference for young students of physics and natural science „Openreadings 2011”, Vilnius, Lithuania, March 16-19,2011

1. K.Pudzs, A.Vembris, I.Muzikante, J.V.Grazulevicius, Energy structure of thin film determination in light emitting diode, Book of Abstracts,p.100

Pages:     | 1 |   ...   | 22 | 23 || 25 | 26 |

Similar works:

«This article was originally published in the newsletter of the Sophia Foundation: Starlight, vol. 14, no. 1 (Easter 2014), available in PDF format as a free download from www.sophiafoundation.org. The Transition Robert Powell and Keith Harris As a prelude to the main content of the following article, we the authors wish to offer the reader some background concerning this article. The idea for this theme of “The Transition” came from Keith. It is related to, and is a continuation from, his...»

«www.ccsenet.org/ies International Education Studies Vol. 3, No. 4; November 2010 The Rise of African Drumming among Adult Music Learners in Hong Kong Hung Kun Lee EdD Graduate School of Professional and Continuing Education University of Hong Kong E-mail: leepercussion@ymail.com Abstract The present study aims at further examining an interesting finding of a recent empirical research on Hong Kong adults’ participation in African drumming from a sociological perspective by adopting some...»

«DOCKETED 1/28/14   USNRC PRM-51-30   OFFICE OF THE SECRETARY Originally submitted on December 20, 2013 Corrected Comments submitted on January 7, 2014 UNITED STATES OF AMERICA BEFORE THE NUCLEAR REGULATORY COMMISSION ) In the Matter of ) ) Proposed Rule: Waste Confidence – ) Continued Storage of Spent Nuclear Fuel ) Docket No. 2012-0246 10 C.F.R. Part 51 ) ) Draft Waste Confidence Generic ) Environmental Impact Statement ) ) Comments by Environmental Organizations on Draft Waste Confidence...»

«Bennett School of Irish Dance Feis 101 The Basic Stuff You Need to Know About Irish Dancing Competition by Bill Bennett 06/17/15 1. Feiseanna, Oireachtaisi, and their Kin A feis (pronounced “fesh”, plural “feiseanna”) is the local level of Irish dancing competition. The Gaelic word originally meant simply, “a gathering”. A sanctioned feis is one that is registered with the North American Feis Commission and follows its rules. Among the rules that a feis must follow in order to be...»

«African Sociological Review, 10, (1), 2006, pp. 221-230.RESEARCH REPORT The Use of Documentary Research Methods in Social Research Monageng Mogalakwe Department of Sociology University of Botswana Gaborone, Bostswana Introduction Social research is an activity that is undertaken to find an answer or explanation regarding a particular social phenomenon. It involves systematic collection of data about such a social phenomenon for the purpose of finding and or understanding patterns and...»

«Matthews et al. Fashion and Textiles (2015) 2:26 DOI 10.1186/s40691-015-0050-9 Open Access RESEARCH The Michelle Obama influence: an exploration of the first lady’s fashion, style, and impact on women Delisia Matthews1*, Cassandra Chaney2 and Jane A. Opiri3 *Correspondence: Abstract drmatthe@ncsu.edu Textile and Apparel, Given keen national interest in the fashion sense of First Lady Michelle Obama, few Technology studies have examined the appeal of the first lady’s style and if her...»

«Date of Submission: September 28, 2015 PIA ID Number: 1568 A. SYSTEM DESCRIPTION 1. Enter the full name and acronym for the system, project, application and/or database. Customer Account Data Engine 2, CADE 2 2. Is this a new system? No 2a. If no, is there a PIA for this system? Yes If yes, enter the full name, acronym, PIA ID Number and milestone of the most recent PIA. Customer Account Data Engine 2, CADE 2 Next, enter the date of the most recent PIA. 6/24/2015 Indicate which of the following...»

«Chapter 7 The design of MIRA 7.1 Introduction The MIRA learning environment was built with the main purpose of testing the Reflection Assistant model and allowing empirical studies. This chapter presents the design of MIRA and the functionalities implemented at the metacognitive and domain levels.7.2 Main Features The Metacognitive Instruction using a Reflective Approach system (MIRA) is a problem solving learning environment built in Java. The main focus in the design of MIRA was to create a...»

«kartenlegen kostenlos kartenlegen kostenlos Kartenlegen kostenlos | Vistano.de Kostenlos Kartenlegen für Neukunden live am Telefon. Jetzt testen! Spirituelles Kartenlegen | astrowelt.com Kartenlegen,Wahrsagen und Hellsehen 24/7 Live und direkt am Telefon Mächtige Partnermagie. | Hellseher-Magier.com Liebeszauber und Partnerrückführung Erfolg seit über 26 Jahren Kartenlegen am Telefon | astrolantis.de Spirituelles Kartenlegen von erfahrenen Hellsehern und Kartenlegern. Kartenlegen Kostenlos...»

«Data Abstraction Architecture for Spacecraft Autonomy Scott Bell and David Kortenkamp TRACLabs Inc. 1012 Hercules Houston Texas 77058 korten@traclabs.com Jack Zaientz Soar Technology Inc. 3600 Green Court, Suite 600 Ann Arbor, MI 48105 Spacecrafts generate huge amounts of data. A significant challenge for autonomous control systems and human operators is ensuring that the right data (and combinations of data) are available at the right time for control and decision-making and ensuring that the...»

«543-0038-01, 543-0071-00, 543-0038-02, 943-0038-01, 943-0038-02 User’s Manual Comfort Alert® Diagnostics – Faster Service And Improved Accuracy The Comfort Alert diagnostics module is a breakthrough innovation for troubleshooting and protecting three phase Copeland Scroll® compressors. The module installs easily in the electrical box of the condensing unit near the compressor contactor. By monitoring and analyzing data from the Copeland Scroll compressor and the thermostat demand, the...»

«Servicebeschreibung: Dell Vor-Ort-Service für Drucker am nächsten Arbeitstag (Vor-Ort-Druckerservice) I. Überblick über den Vor-Ort-Druckerservice Wir haben unseren Service so gestaltet, dass eine Störung des erworbenen Dell-Geräts möglichst schnell und einfach behoben wird. Sollte der Drucker einen Fehler aufweisen, der sich per Telefon nicht lösen lässt, entsendet Dell im Rahmen des Vor-Ort-Druckerservice einen Service-Techniker an den Standort des Kunden nach Abschluss der unten...»

<<  HOME   |    CONTACTS
2016 www.thesis.xlibx.info - Thesis, documentation, books

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.