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IDEAS 471/2008
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ELECTRICAL TRANSPORT IN LOW DIMENSIONAL GE-SI-O SYSTEMS:

EXPERIMENT AND MODELLING

Project Coordinator: National Institute of Materials Physics

Project Director: Dr. Magdalena Lidia Ciurea

Abstract Objective
Activities
Results

Abstract

There are few papers in the literature concerning the electrical properties of low dimensional ge-si-o systems, compared with those concerning the luminescence, raman scattering, microstructure etc. the aim of the present project is the experimental study and modelling of the electrical transport phenomena in low dimensional systems (0D, 1D and 2D).

In order to achieve this aim, we propose the following objectives: (1) preparation of ge-si-o layers with variable composition, formed by dots immersed in an amorphous matrix, and investigation of electrical transport phenomena in correlation with the composition and microstructure (0D systems); (2) preparation, microstructure characterization and electrical investigation of layers formed by nanowires (1D systems); (3) deposition of mono- and multilayer nanostructures (2D systems) and study of their electrical behaviour (4) modelling of electrical transport processes in 0D, 1D and 2D systems; (5) dissemination of the results. at the same time, we will form young researchers, highly qualified in in the field of the project. the aim and the objectives of the project are in agreement with the derivate objectives of the program ideas, from the romanian national rdi program pncdi ii, and are also framed in the main research directions in the world.

The original expected results are: determination of the transport mechanisms in 0D, 1D and 2D systems; elaboration of a (unitary) model of quantum confinement for 0D, 1D and 2D systems; study of percolation processes in in 0D and 1D systems; study of interface localized charges. these results represent novelty elements, important for the top field of the nanosciences. the dissemination of the results will be performed by means of the setting-up of a web page (that will be permanently updated), 4 articles in isi-quoted journals, 7 international conferences contributions, and 4 self-evaluation reports, with public presentation in the frame established by the funds provider.

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Objectives

(1) preparation of GexSi1-xOy layers with variable composition, formed by dots immersed in an amorphous matrix, and investigation of electrical transport phenomena in correlation with the composition and the microstructure (0D systems);

(2) preparation, microstructure characterization and electrical investigation of layers formed by nanowires (1D systems);

(3) deposition of mono- and multilayer nanostructures (2D systems) and study of their electrical behaviour;

(4) modelling of electrical transport processes in 0D, 1D and 2D systems;

(5) dissemination of the results.

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Activities

Stages

Activities

Calendar

Stage I

1. Preparation of GexSi1-xOy layers with variable composition, formed by dots immersed in an amorphous matrix, and investigation of electrical transport phenomena in correlation with the composition and the microstructure (0D systems):
      1.1. Deposition of amorphous layers by sol-gel.
      1.2. Deposition of amorphous layers by magnetron sputtering.
      1.3 Composition measurements (EDX, XPS).
      1.4 Thermal annealing for dot nucleation.


3. Dissemination of the results.
      3.1. Setting-up the project web page (in Romanian and English).
      3.2. Elaboration of the self-evaluation report.
      3.3. 1 international conferences contribution (ex. ROCAM 2009        Brasov).

15 sept 2009

Stage II

1. Preparation of GexSi1-xOy layers with variable composition, formed by dots immersed in an amorphous matrix, and investigation of electrical transport phenomena in correlation with the composition and the microstructure (0D systems):
      1.5. Structural characterisation (SEM, TEM, HRTEM, SAED).

3. Dissemination of the results.
      3.1. Updating the web page. (in Romanian and English).
      3.2. Elaboration of the self-evaluation report.
      3.3.1 ISI paper and 1 international conferences contributions. (ex. CAS 2009 Sinaia)

15 dec 2009

Stage III

1. Preparation of GexSi1-xOy layers with variable composition, formed by dots immersed in an amorphous matrix, and investigation of electrical transport phenomena in correlation with the composition and the microstructure (0D systems).
      1.6. Contacts deposition (in sandwich and/or coplanar configuration).
      1.7. Experimental investigation of electrical transport phenomena.

2. Preparation and characterization of Si stabilized layers formed by nanowires (1D systems).
      2.1. Preparation of 1D systems by electrochemical etching and stabilization by treatment under controlled conditions.
      2.2. Structural characterization (SEM, TEM, HRTEM, SAED);
      2.3. Contacts deposition (in sandwich and/or coplanar configuration).
      2.4. Experimental investigation of electrical transport phenomena.

3. Modelling of electrical transport processes in 0D, 1D and 2D systems.
     3.1 Study of dominant conduction mechanisms in 0D systems.
     3.2 Computing the quantum confinement levels in 0D systems.
     3.3 Analysis of the dot/matrix interface.
     3.4 Analysis of transport mechanisms in 1D systems.

4. Dissemination of the results.
    4.1. Setting-up the project web page (in Romanian and English).
    4.2. Elaboration of the self-evaluation report.
    4.3. 1 ISI papers and 2 international conferences contributions.

10 dec 2010

Stage IV

 

 

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Results

2009

Published Papers

1.“The influence of shape and potential barrier on confinement energy levels in quantum dots”, Ana-Maria Lepadatu, Ionel Stavarache, Magdalena Lidia Ciurea and Vladimir Iancu, acceptata pentru publicare in Journal of Aplied Physics

2."Calculation of the quantum efficiency for the absorption on confinement levels in quantum dots", Vladimir Iancu, Mihai Razvan Mitroi, Ana-Maria Lepadatu, Ionel Stavarache, and Magdalena Lidia Ciurea, trimisa spre publicare la Journal of Nanoparticle Research .

3.“Structural investigations of Ge dots embedded in SiO2”, I. Stavarache, A.-M. Lepadatu, T. F. Stoica, G. Stan, D. Marcov, A. Slav, V. S. Teodorescu, N. Gheorghe, C. M. Teodorescu, G. Iordache and M. L. Ciurea, trimisa spre publicare la Journal of Nanoparticle Research

4."Quantum Confinement in Nanometric Structures", Magdalena Lidia Ciurea and Vladimir Iancu, capitolul 5, (14 pag). in cartea "New Trends in Nanotechnology and Fractional Calculus Applications", Editori D.Baleanu, Ziya B. Guvenc and J. A. Tenreiro Machado, carte in curs de publicare, Book lD 157858_Chap1D 005_Proof# 1 - 14/10/09 editura Springer.

Conferences & Workshops

1.“The influence of the quantum dot shape on the quantum confinement energy levels”, A.-M. Lepadatu, E. Rusnac, I. Stavarache, V. S. Teodorescu, M L Ciurea, and V Iancu, E-MRS 2009 Spring Meeting, Symposium D : Nano-scale energetic materials: fabrication, characterization and molecular modeling, June 8 -12, 2009 Strasbourg (France).

2.“Evaluation of the internal quantum efficiency for supplementary absorption on quantum confinement levels”, V Iancu, M R Mitroi A-M Lepadatu, I. Stavarache, G. Iordache, and M L Ciurea, E-MRS 2009 Spring Meeting, Symposium B : Inorganic and Nanostructured Photovoltaics (INP), June 8 -12, 2009 Strasbourg (France).

3.“Structural investigations of Ge dots embedded in SiO2”, I. Stavarache, A.-M. Lepadatu, T. F. Stoica, G. Stan, D. Marcov, A. Slav, V. S. Teodorescu, C. M. Teodorescu, A. M. Vlaicu, I. Pasuk, S. Lazanu, G. Iordache and M. L. Ciurea, Romanian Conference on Advanced Materials, ROCAM 2009, August 25 – 28, Brasov (Romania).

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Results

2010

Published Papers

1. “Calculation of the quantum efficiency for the absorption on confinement levels in quantum dots”, Vladimir Iancu, Mihai Razvan Mitroi, Ana-Maria Lepadatu, Ionel Stavarache, Magdalena Lidia Ciurea, J. Nanopart. Res. 2010, DOI 10.1007/s11051-010-9913-6, Factor de impact: 2.478 (2009).

2. “Structural investigations of Ge nanoparticles embedded in an amorphous SiO2 matrix”, Ionel Stavarache, Ana-Maria Lepadatu, Nicoleta G. Gheorghe, Ruxandra M. Costescu, George E. Stan, Dan Marcov, Adrian Slav, Gheorghe Iordache, Tionica F. Stoica, Vladimir Iancu, Valentin S. Teodorescu, Cristian M. Teodorescu, Magdalena Lidia Ciurea, J. Nanopart. Res. 2010, DOI 10.1007/s11051-010-0021-4, Factor de impact: 2.478 (2009).

3. Study of Ge nanoparticles embedded in an amorphous SiO2 matrix with photoconductive properties”, autori A. M. Lepadatu, I. Stavarache, T. F. Stoica, M. L. Ciurea,  acceptata pentru publicare in Digest Journal of Nanomaterials and Biostructures (trim I 2011), Factor de impact: 1.75 (2009)..

 

Indexed ISI papers (only 2010)

1.Influence of preparation method on structural properties of GeSiO systems”, autori I. Stavarache, A.-M. Lepadatu, V. Teodorescu, T. Stoica, I. Pasuk, G. Stan, V. Iancu, M. L. Ciurea, Proc. IEEE Conf, IEEE Catalog No. CFP10CAS-PRT, ISBN: 978-1-4244-5781-6, ISSN: 1545-827X, vol. 1, pp. 77-80 (2010)

2. “Temperature dependence of capture coefficients in trapping phenomena”, autori A.-M. Lepadatu, I. Stavarache, S. Lazanu, V. Iancu, M. R. Mitroi, R. R. Nigmatulin, M. L. Ciurea, Proc. IEEE Conf, IEEE Catalog No. CFP10CAS-PRT, ISBN: 978-1-4244-5781-6, ISSN: 1545-827X, vol. 2, pp. 371-374, (2010)

 

Communications

1. “Quantum confinement energy levels in silicon quantum dots”, M. L. Ciurea, V. Iancu, A.-M. Lepadatu, I. Stavarache, CNF 2010, Conferinta Nationala de Fizica - Iasi 23-25 septembrie 2010.

Poster presented by Drd. A.-M. Lepadatu

2. “Voltage percolation thresholds in different nanosystems”, I. Stavarache, A.-M. Lepadatu, V. Iancu, M. L. Ciurea, PM-I6

The 6th Colloquium “Mathematics and Physics in Engineering, Numerical Physics and Complexity” (MENP–6), joint with the 2nd Colloquium “Physics of Materials” (PM–2).

 Oral presentation Dr. M. L. Ciurea 

3. “Temperature dependence of the dark current in GeSiO nanosystems”,I. Stavarache, PM-O7

The 6th Colloquium “Mathematics and Physics in Engineering, Numerical Physics and Complexity” (MENP–6), joint with the 2nd Colloquium “Physics of Materials” (PM–2).

Oral presentation Drd. I. Stavarache 

4. “Electrical transport at room temperature in GeSiO nanosystems”, A.-M. Lepadatu, NP-O3

The 6th Colloquium “Mathematics and Physics in Engineering, Numerical Physics and Complexity” (MENP–6), joint with the 2nd Colloquium “Physics of Materials” (PM–2).

Oral presentation Drd. A.-M. Lepadatu

5.  “Optical transmission through Si-SiO2 nanocomposites with variable concentration of Si nanocrystals”, I. Stavarache, C. Palade, A.-M. Lepadatu, PM-P1

The 6th Colloquium “Mathematics and Physics in Engineering, Numerical Physics and Complexity” (MENP–6), joint with the 2nd Colloquium “Physics of Materials” (PM–2).

 Presented by Masterand C. Palade

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Results

2011

Published Papers (ISI):

1. “Voltage percolation thresholds evidenced in the electrical behaviour of different nanostructures”,

   I. Stavarache, Digest Journal of Nanomaterials and Biostructures, 6, 1073 – 1083 (2011).

 2.Numerical analysis of J–V characteristics of dye-sensitized solar cells”, a M. R. Mitroi, L. Fara si M. L. Ciurea, trimisa pentru publicare (4.04.2011) la Progress in Photovoltaics: Research and Application.

3. “Structure and electrical transport in films of Ge nanoparticles embedded in SiO2 matrix”, I. Stavarache, A.-M. Lepadatu, A. V. Maraloiu, V. S. Teodorescu si M. L. Ciurea, trimisa pentru publicare (28.09.2011) la Journal of Nanoparticle Research.

4. “Calculation of the quantum efficiency for the absorption on confinement levels in quantum dots”, V. Iancu, M. R. Mitroi, A.-M. Lepadatu, I. Stavarache, M. L. Ciurea, Journal of Nanoparticle Research 13, 1605 – 1612 (2011).

5. “Structural investigations of Ge nanoparticles embedded in an amorphous SiO2 matrix”, I. Stavarache, A.-M. Lepadatu, N. G. Gheorghe, R. M. Costescu, G. E. Stan, D. Marcov, A. Slav, G. Iordache, T. F. Stoica, V. Iancu, V. S. Teodorescu, C. M. Teodorescu, M. L. Ciurea, Journal of Nanoparticle Research 13, 221 – 232 (2011).

6. “Structural investigations of Ge nanoparticles embedded in an amorphous SiO2 matrix”, A.-M. Lepadatu, I. Stavarache, T. F. Stoica, M. L. Ciurea, Digest Journal of Nanomaterials and Biostructures, 6, 67 – 73 (2011).

 

Indexed ISI paper:

1. ”Preparation and electrical characterization of SiGe nanostructures”, I. Stavarache, A.-M. Lepadatu, I. Pasuk, V. S. Teodorescu si M. L. Ciurea, Proc. IEEE CN CFP11CAS-PRT, ISBN: 978-1-61284-171-7, 1, pp. 49-52.

2. ”Preparation induced elecrical behaviour of GeSiO nanostructures”, I. Stavarache, A.-M. Lepadatu si M. L. Ciurea, Proc. IEEE CN CFP11CAS-PRT, ISBN: 978-1-61284-171-7, 1, pp. 31-34.

 

Books:

1. Capitol 3 “Quantum Well Solar Cells- Physics, Materials and Technology” in “Advanced Solar Cell   Materials, Technology, Modeling and Simulation”, M. L. Ciurea, A.-M. Lepadatu si I. Stavarache, editura IGI Global, editori L. Fara si  M. Yamaguchi.

2. Capitol Ge nanodots embedded in a silica matrix”, I. Stavarache, A.-M. Lepadatu si M. L. Ciurea, editura Academiei Romane, Bucuresti 2011.

 

Communications at national and international conferences

1. “Electrical Transport in Films of Ge Nanoparticles Embedded in Amorphous SiO2 Matrix”, M. L. Ciurea, Nano and Giga Challenges in Electronics, Photonics and Renewable Energy Symposium and Summer School, Moscow - Zelenograd, Russia, September 12-16, 2011.

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Updated: 31 ian 2012 - Ionel Stavarache: stavarache@infim.ro

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