BrainMap

Ana-Maria Lepadatu

Senior Researcher - INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Researcher | Scientific reviewer

Ana-Maria Lepadatu received her Ph.D. in Physics in 2012 from the University of Bucharest under the supervision of Professor Magdalena Lidia Ciurea. She is now Senior Researcher in the Group of Nanomaterials and Nanostructures based on SiGeSn at National Institute of Materials Physics, Magurele, Romania. Her research focuses on characterization of films and nanostructures based on group IV Si-Ge-Sn nanocrystals embedded in oxide matrix regarding energy structure, Raman spectroscopy, electrical, photoelectrical and charge storage properties by experiment and modelling / simulation.

Web of Science ResearcherID: O-8147-2014

Curriculum Vitae (20/02/2024)

Expertise & keywords

Multifunctional optoelectrical sensor based on two-dimensional MoS2 atomically thin layers grown by selective nucleation Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2021-2457 2022 - 2024

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation:

Project website: https://infim.ro/en/project/multifunctional-optoelectrical-sensor-based-on-two-dimensional-mos2-atomically-thin-layers-grown-by-selective-nucleation/

Abstract:

Optoelectrical multifunctional sensors will be obtained based on selective nucleation and growth of two-dimensional 2D-MoS2 atomically thin layers on SiO2/Si patterned substrates, by using Physical Vapor Deposition method. The substrate patterning will be performed by deposition of Mo pads before growth of MoS2 flakes. The precise localization of selectively grown 2D-MoS2 flakes allows the fabrication of the optoelectrical sensors by deposition of metallic contacts using photolithographic technique with alignment to the patterns of the substrate. The atomically thin 2D-MoS2 layers are very sensitive to external excitation as for example light illumination or adsorbed molecules on the 2D-MoS2 free layer surface. Using the Si substrate as gate electrode, the (photo)sensitivity of the device can be controlled and enhanced by field effect. Based on the high sensitivity expressed by electric and photoelectric behaviour, the 2D-MoS2 optoelectrical sensors are recommended for many practical applications, as for example biosensors (protein detection, DNA compatibility, acetone in human breath for diabetes, etc) and chemical sensors for pollution monitoring. The validation of the optoelectrical sensor demonstrator in this project according to TRL 3 includes the testing experiments on spectral photocurrent, as well as on electrostatic doping in 2D-MoS2 layers by field effect and adsorbed acetone molecules.

Synaptic neuron-like structure based on HfO2/GeSn with ferroelectric field effect that simulates a three-terminal memristor Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente - TE-2021
PN-III-P1-1.1-TE-2021-1537 2022 - 2024

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation:

Project website: https://infim.ro/en/project/synaptic-neuron-like-structure-based-on-hfo2-gesn-with-ferroelectric-field-effect-that-simulates-a-three-terminal-memristor/

Abstract:

This project propose the development of a synaptic structure based on HfOx/GexSn1-x with conductance modulated by ferroelectric field-effect. By improving the ferroelectric characteristics of HfOx using a high-mobility channel material (epi/poly GeSn) we obtain a synaptic neuron-like structure that simulate a three-terminal memristor for neuromorphic computing. The HfOx/GexSn1-x structure is obtained by reactive/non-reactive magnetron sputtering followed by Rapid Thermal Annealing in active working gas (H2/N2) to avoid the local disorder by passivating the dangling bonds and by healing the trap states. The remanent polarization will be enhanced for HfOx/GexSn1-x structure by controlling the interface between HfOx FeCAP and the GeSn high-mobility channel. The HfOx/GexSn1-x layers structure is morphological and structural characterized by XRD, XPS, HRTEM, and electrical measurements of the ferroelectric field-effect.

Photodetectors with GeSn nanocrystals in Si3N4 matrix highly photosensitive from 0.5 µm to 2.4 µm Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente - TE-2021
PN-III-P1-1.1-TE-2021-1491 2022 - 2024

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation:

Project website: https://infim.ro/en/project/photodetectors-with-gesn-nanocrystals-in-si3n4-matrix-highly-photosensitive-from-0-5-%c2%b5m-to-2-4-%c2%b5m/

Abstract:

The project goal is to fabricate a demonstrator for photodetector device with GeSn-nps (top contact/GeSn-nps:Si3N4/Si and/or quartz substrate/bottom contact), having targeted parameters: photocurrent to dark current ratio at least 2 orders of magnitude, fast photoresponse time:μs, spectral window extended toward 2.4 µm, high responsivity and good detectivity characteristics. We propose a new and original approach, by using an active layer that give an extended spectral limit in SWIR due to Si3N4 properties to induce a tensile strain in film. This consists in co-deposition or multilayer of different GeSn compozition and content in Si3N4. Objectives: O1: Fabrication by MS of the structure, GeSn-nps:Si3N4/ Si or quartz substrate, by using different novel approaches. For this, the critical deposition parameters (target power, work pressure, gas flux or substrate temperature) will be finely tuned to be optimized. O2: Formation of the GeSn-nps in Si3N4 matrix with controlled morphology (size, uniformity and density); O3: Developing the test samples with photoconductive properties controlled by morphology, completely characterized; O4: Obtaining the demonstrator of the photodetector device having targeted parameters, functionally tested according to TRL 3. Dissemination of the results: 1 patent, 3 ISI-quoted journals, 2 contributions to conferences and web page. The team expertise and facilities chosen to reach the project goal is a strong argument for the success of this project.

Multilayered floating gate nonvolatile memory device with GeSi nanocrystals nodes in nanocrystallized high k HfO2 for high efficiency data storage Call name: P 4 - Proiecte de Cercetare Exploratorie, 2020
PN-III-P4-ID-PCE-2020-1673 2021 - 2023

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation:

Project website: https://infim.ro/en/project/multilayered-floating-gate-nonvolatile-memory-device-with-gesi-nanocrystals-nodes-in-nanocrystallized-high-k-hfo2-for-high-efficiency-data-storage-multigesincmem/

Abstract:

The project goal is to fabricate a multilayered floating gate (FG) nonvolatile memory device (ML NVM) with charge storage nodes of GeSi nanocrystals (NCs) embedded in nanocrystallized high k HfO2 matrix (capacitor of top contact/ gate HfO2/ n layers of GeSi NCs in HfO2 as FG/ tunnel HfO2/ Si wafer/ bottom contact, n=1 to 5 for the 5 versions NVM1-NVM5). We target in project to obtain high performance ML NVMs (memory window >4 V, charge loss ratio

Controlling the electronic properties in heterostructures based on ferroelectric perovskites: from theory to applications Call name: P 4 - Proiecte Complexe de Cercetare de Frontieră
PN-III-P4-ID-PCCF-2016-0047 2018 - 2022

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU TEHNOLOGII IZOTOPICE SI MOLECULARE I N C D T I M (RO); UNIVERSITATEA POLITEHNICA DIN BUCURESTI (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/en/project/control-of-electronic-properties-in-ferroelectric-perovskite-heterostructures-from-theory-to-applications/

Abstract:

The main objective of the project is to obtain ferroelectric materials with controlled electronic properties at the same level as this properties are controlled in Si. This will be realized by hetero-valent doping, correlated with stress engineering and band gap engineering without affecting, as much as possible, the ferroelectric properties. The main objective is complex and ambitious because, up to date, there was no experimental demonstration that it possible to obtain n or/and p type conduction in epitaxial ferroelectrics. The successful achievement of this objective will open a new domain, that of ferroelectric electronics or ferrotronics, by producing electronic devices of p-n homo-junction type or junction transistors with ferroelectric materials. Two types of materials are envisaged, namely lead titanate-zirconate (PZT with tetragonal structure and a mixed bismuth ferrite (BFO) with bismuth chromit (BCO). In the first case the heterovalent doping will be studied on Pb or Zr/Ti sites with the aim to obtain n and p type conduction. The final goal is to produce a p-n homo-junction based on epitaxial PZT films. In the second case band gap engineering will be tested by varying the Fe/Cr content, and the dominant conduction mechanism will be identified, the goal being to use the material in photovoltaic applications. The activities will contain: theoretical studies regarding the relation between dopants, electronic properties and the ferroelectricity, including self-doping effects or electrostatic doping; target preparation for deposition of thin films; epitaxial growth of the film; characterization activities of the structure and physical properties. Not only classic doping in the target is envisaged but also doping during the epitaxial growth. The consortium is composed of 4 teams from three different institutions, including a number of 14 young researchers full time equivalent.

Broadband photodetector based on hydrogenated GeSn layers. Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2019-4468 2020 - 2022

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/en/project/broadband-photodetector-based-on-hydrogenated-gesn-layers/

Abstract:

The main goal of this project is the obtaining by magnetron sputtering (MS) deposition and hydrogenation of GexSn1-x:H alloy, a new photosensitive material for fabrication of high sensitive broadband photodetectors. By increasing the Sn concentration in GeSn alloy, the bandgap is narrowed and changed from indirect to direct bandgap semiconductor, making GeSn a good candidate for photodetectors with extended sensitivity to short-wave infrared range (SWIR). At international level, the hydrogenation of GexSn1-x to obtained amorphous and nanocrystalline GexSn1-x:H represents the novelty of the project proposal. The role of hydrogen in GexSn1-x:H alloy is to passivate the structural unintended defects, in order to increase the photosensitivity. This is similar to other semiconductors based on group IV of elements (a-Si:H and a-SiGe:H) intensively studied and reported in literature. Two different technological routes of obtaining GexSn1-x:H will be investigated: i) MS deposition of GexSn1-x films with various Sn content followed by hydrogen plasma treatment at different annealing temperatures; ii) direct deposition of GexSn1-x:H by reactive MS in atmosphere of hydrogen diluted in argon. In both cases, the nanocrystallization will be obtained by in-situ annealing during MS deposition or ex-situ by RTA treatment. For achieving the final goal that of obtaining a broadband photodetector with high sensitivity in SWIR, complex characterizations of GexSn1-x:H layers will be performed to find out the optimal technological parameters of the demonstrator. The demonstrator will be functionally tested in the lab according to TRL3. Such photodetectors with high sensitivity in SWIR are imperatively desired to replace the actual market devices based on toxic materials PbS and InGaAs. The results of the project activities may serve to future research on GexSn1-x:H for other practical applications as for example tandem a-SiGeSn:H solar cells.

Non-volatile memory based on ferroelectric HfO2 Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2019-0205 2020 - 2022

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: https://infim.ro/en/project/non-volatile-memory-based-on-ferroelectric-hfo2-ferohafomemo/

Abstract:

The project scope is to fabricate a nonvolatile memory (NVM) demonstrator based on ferroelectric HfO2 with targeted parameters of 1.5–2 V memory window and good retention, starting from TRL 2 up to TRL 3. This device benefits from ferroelectric HfO2 advantages: low influence of parasitic charge trapping on NVM performance (high memory window of 1.5–2 V); CMOS compatibility; lateral and vertical gate-stack scaling; low power operation. The project objectives are: O1) magnetron sputtering deposition of NVMs in 3 versions (V1-V3) using 2 approaches of undoped and Ge-doped HfO2: V1) HfO2/Hf/HfO2/ Si (100), V2) (HfO2/Hf)n/ Si (100) with n = 1 and 2, V3) (HfO2/ZrO2)n/ Si (100); O2) Obtaining ferroelectric HfO2 or HfZrO phase in NVMs by post-deposition rapid thermal annealing (RTA) performed on versions V1-V3 and consolidation of ferroelectricity by post-metallization annealing (PMA); RTA and PMA represent new solution; O3) Obtaining good contacts (Pt, Al); O4) Developing test samples completely characterized (NVM properties, morphology, structure); O5) Fabrication of NVM demonstrator “metal contact/ferroelectric HfO2 or HfZrO/Si (100)/metal contact”; testing of functional parameters/characteristics at TRL 3. The project is beyond state of art and has high level of novelty as it proposes new solutions of new advanced materials and new technological approaches for NVM fabrication: *controlling density of O vacancies in HfO2 by controlling Ar/O2 ratio during deposition and by depositing Hf layer between/near HfO2 layers (V1, V2); *Ge doping of HfO2 and HfZrO (V1-V3); *tailoring layers thicknesses in V3. Results: i) scientific ones - 1 ISI paper and dissemination at prestigious international conferences in the field by 2 papers; ii) technological - 1 patent application. Experienced and postdoctoral researchers ensure the project accomplishment based on their high level expertise, and project team will gain new competences and EU and international visibility in NVMs field.

Advanced nanoelectronic devices based on graphene/ferroelectric heterostructures (GRAPHENEFERRO) Call name: P 4 - Proiecte Complexe de Cercetare de Frontieră
PN-III-P4-ID-PCCF-2016-0033 2018 - 2022

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE- DEZVOLTARE PENTRU MICROTEHNOLOGIE - IMT BUCURESTI INCD

Project partners: INSTITUTUL NATIONAL DE CERCETARE- DEZVOLTARE PENTRU MICROTEHNOLOGIE - IMT BUCURESTI INCD (RO); UNIVERSITATEA BUCURESTI (RO); INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.imt.ro/grapheneferro/

Abstract:

Applications such as high-frequency and neuromorphic circuits, optoelectronic/plasmonic detection of biomolecules or thermo-opto-electronics energy harvesting, require tunable and reconfigurable functionalities. Graphene is suitable for these applications because of electrostatic doping, its optical constants being tuned via gate voltages. However, oxide substrates limit the mobility in graphene to few thousands cm2/V•s. On the contrary, the mobility in graphene/ferroelectric (G/F) heterostructures is 2-3 orders of magnitude larger. The groundbreaking nature of the project is based on the possibility of significantly enhancing the functionality of graphene-based transistors/devices by using crystalline ferroelectric substrates instead of common oxides or SiC substrates. The G/F heterostructures allow: (i) the achievement of very high mobilities in G/F field effect transistors (FETs), which push the transistor gain in the 0.3-1 THz range, far above 70 GHz at which the maximum gain is attained nowadays, (ii) the fabrication of uncooled tunable detectors working in the THz and IR, (iii) the exploitation of the hysteretic resistance behaviour, essential for neuromorphic applications such as artificial synapses, (iv) the fabrication of reconfigurable microwave circuits, and (v) of tunable thermoelectronic devices, since graphene displays a giant thermoelectric effect. The project will consist of the design, fabrication and testing of groundbreaking, innovative nanoelectronic devices, in particular ultrafast electronic devices, neuromorphic circuits for computation, reconfigurable and harvesting devices, all based on the outstanding physical properties of G/F heterostructures. All fabrication techniques for growing graphene-ferroelectric heterostructures in this project should be scalable at wafer scale. The project is implemented by a consortium of 3 national R&D institutes and the leading Romanian university, which have the necessary advanced infrastructure.

New advanced nanocomposites. Technological developments and applications Call name: P 1 - SP 1.2 - Proiecte complexe realizate in consorții CDI
PN-III-P1-1.2-PCCDI-2017-0871 2018 - 2021

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE PENTRU OPTOELECTRONICA INOE 2000 INCD (RO); UNIVERSITATEA DE VEST TIMISOARA (RO); ACADEMIA ROMANA FILIALA TIMISOARA (RO); UNIVERSITATEA BABES BOLYAI (RO); INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE PENTRU FIZICA TEHNICA-IFT IASI (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA LASERILOR, PLASMEI SI RADIATIEI - INFLPR RA (RO); INSTITUTUL NATIONAL DE CERCETARE- DEZVOLTARE PENTRU MICROTEHNOLOGIE - IMT BUCURESTI INCD (RO); UNIVERSITATEA "DUNAREA DE JOS" (RO); UNIVERSITATEA TRANSILVANIA BRASOV (RO); Ministerul Apararii Nationale prin Centrul de Cercetare Stiintifica pentru Aparare CBRN si Ecologie (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/project/kuncser_noi_directii_de_dezvoltare_tehnologica_si_utilizare_nanocompozite_avansate_47pccdi_2018

Abstract:

The development of complex nanocomposite materials consisting of different matrices (polymer-like, oxides, intermetallics, liquids) functionalized by different nasnostructured additions (carbon allotropes, magnetic nanoparticles with different organizations, nanostructured semiconductors, etc.) is the aim of this project. The unique combinations of interacting nanophases offeres to the hybrid nanocomposite material new or enhanced proprieties of high interest for applications. In this context, according to the previous experience of the involved teams, the complex project (formed by 4 component projects) is focused on the development of new optimized nanocomposite systems to be included in experimental demonstrators or final products to be transferred to economical companies. The project will contribute both to an increased scientific visibility of the partners as well as to enhancing the institutional performances by the development of new technical and scientific capacities.

Technologic paradigms in synthesis and characterization of variable dimensionality systems Call name: P 1 - SP 1.2 - Proiecte complexe realizate in consorții CDI
PN-III-P1-1.2-PCCDI-2017-0152 2018 - 2021

Role in this project: Key expert

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE PENTRU TEHNOLOGII CRIOGENICE SI IZOTOPICE - I.C.S.I. RAMNICU VALCEA (RO); UNIVERSITATEA DE VEST TIMISOARA (RO); INSTITUTUL NATIONAL DE CERCETARE- DEZVOLTARE PENTRU MICROTEHNOLOGIE - IMT BUCURESTI INCD (RO); INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE PENTRU FIZICA TEHNICA-IFT IASI (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/project/vardimtech/, http://infim.ro/project/vardimtech-en

Abstract:

Last decades brought a considerable development of technologies based on ordered systems. Starting with semiconductor physics and photovoltaics, technologies soon evolved towards the utilisation on large scale of thin films and of surface / interface properties. Example go nowadays from data storage and readout (electrostatic or magnetic memories, giant magnetoresistance) to catalysis, gas sensors or photocatalysis (surface phenomena), and towards interfaces with biological matter (biosensors, templates for tissue reconstruction, interfaces between biological electrical signals and microelectronics). In Romania, crystal growth is performed since half a century; nevertheless, during the last years these activities fade out and need to be seriously reinforced, especially with the advent of new laser and detector technologies required by the Extreme Light Infrastructure facilities. Also, surface science started to be developped seriously only during the last decade, together with techniques involving self-organized nanoparticles, nanoparticle production etc. The main goal of this Project is to gather the relevant experience from the five partners, namely the experience in crystal growth from the University of Timișoara, with the surface science, nanoparticle and nanowire technologies developped by NI of Materials Physics, the cryogenic and ultrahigh vacuum techniques provided by the NI for Cryogenic and Isotopic Technologie, and the experience in ordered 2D systems (graphene and the like) owned by the NI for Microtechnologies (IMT). This common agenda will result in a coherent fostering of technologies relying on ordered systems of variable dimensionalities: 0D i.e. clusters or nanoparticles, including quantum dots; 1D i.e. free and supported nanowires and nanofibers; 2D: surfaces, interfaces and graphene-like systems; and 3D crystals of actual technological interest, together with setting up new ultrahigh vacuum, surface science and electron spectroscopy techniques.

SiGeSn nanocrystals with charge storage properties at nanoscale Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente
PN-III-P1-1.1-TE-2016-2366 2019 - 2021

Role in this project: Project coordinator

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/en/project/sigesn-nanocrystals-with-charge-storage-properties-at-nanoscale-sigesnanomem/

Abstract:

The project aims to obtain nanostructured materials based on SiGeSn nanocrystals (NCs) embedded in oxide matrix with charge storage properties for non-volatile memory applications. The material is completely new, beyond the state of the art as no reports on SiGeSn NCs in oxides are to be found in literature. The project goal will be achieved by 5 specific objectives: O1) obtaining trilayer capacitors with the floating gate of SiGeSn NCs embedded in oxide matrix (SiO2, HfO2) by magnetron sputtering deposition and nanostructuring by thermal annealing; O2) morphology and structure characterisation of NCs-based trilayers for optimizing technological parameters; O3) investigation of electrical and charge storage properties and their correlation with structure and morphology; O4) evaluation of memory parameters of SiGeSn NCs based capacitors in function of NCs morphology and composition; O5) dissemination of project results. For this, the trilayer approach will be used aiming to obtain memory capacitor-like structures with floating gate based on SiGeSn NCs playing the role of charge storage nodes, the NCs having optimal size and density, being properly positioned in respect to Si substrate at tunnelable distance as well as being well separated to each other. More than that, the SiGeSn NCs spatial distribution in the floating gate will be optimized for obtaining a 2D array. The memory properties (memory window and retention) will be controlled by varying the NCs composition and size, by obtaining tunnel oxide with high material quality and proper thickness. The good and complementary expertise of team members ensures the implantation of project in a thematic beyond the state of the art. The original scientific results will be published in 5 papers in high impact ISI-ranked journals and presented at prestigious international conferences.

VIS-NIR photodetectors based on germanium nanocrystals embedded into silicon nitride Call name: P 1 - SP 1.1 - Proiecte de cercetare pentru stimularea tinerelor echipe independente
PN-III-P1-1.1-TE-2016-2050 2018 - 2020

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://infim.ro/project/fotodetectori-in-vis-nir-pe-baza-de-nanocristale-de-germaniu-in-matrice-de-nitrura-de-siliciu-geminiphotodet/

Abstract:

The project aim is to fabricate a miniaturized demonstrator for photodetector device based on Ge nanocrystals (top contact/ Ge-ncs:Si3N4/ Si or quartz substrate/ bottom contact), having targeted photodetector parameters as photocurrent to dark current ratio (on/off ratio) of 1-2 orders, extended to near infrared spectral window, high responsivity, good detectivity and fast response time. To achieve this goal, we propose a new solution for fabricating this device, by using an active layer nanostructured in-situ at low temperature (lower than 500 °C), namely Ge-ncs embedded in Si3N4. In order to achieve the project goal, we propose the following objectives: Objective 1: Deposition by Magnetron Sputtering of the structure Ge-ncs:Si3N4/ Si or quartz substrate, by using different novel approaches; For this, the critical deposition parameters (DC and RF power, work pressure, gas flux or substrate temperature) will be finely tuned to be optimized. Objective 2: Formation of the Ge-ncs into Si3N4 matrix with controlled morphology (Ge-ncs size, uniformity and density); Objective 3: Developing the test samples of top contact/ Ge-ncs:Si3N4/ Si or quartz substrate/ bottom contact with photoconductive properties controlled by morphology, completely characterized; Objective 4: Obtaining the demonstrator of photodetector device having targeted photodetector parameters as photocurrent to dark current ratio (on/off ratio) of 1-2 orders, extended to NIR spectral window, high responsivity, good detectivity and response time, functionally tested according to TRL 3. The scientific results will be disseminated by 1 patent, 2 articles in ISI-quoted journals, 2 contributions at conferences and web page. The team scientific expertise and facilities chosen to reach the project goal is a strong argument for the success of this project.

Optoelectric devices based on SiGeSn nanocrystals in oxide matrix Call name: P 4 - Proiecte de Cercetare Exploratorie
PN-III-P4-ID-PCE-2016-0552 2017 - 2019

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/ro/projects/dispozitive-optoelectrice-pe-baza-de-nanocristale-de-sigesn-matrice-oxidica

Abstract:

The goal of the project is the fabrication of optoelectric devices based on SiGeSn nanocrystals (ncs) embedded in oxide matrix for NIR-VIS range. We envisage two devices, optical sensors and photovoltaic devices that are completely new, never reported in literature. A new approach of Sn alloying of currently investigated SiGe ncs will be used.

The project specific objectives are: O1) fabrication of test samples based on SiGeSn ncs embedded in SiO2 for optical and photovoltaic devices (magnetron sputtering deposition, thermal treatment, electrical contacts); O2) complex characterisation of test samples for structure, composition, crystallinity, ncs morphology, electrical and optical properties and their correlation; O3) simulation of optical sensor and photovoltaic device; O4) fabrication and characterisation of optical sensor; O5) fabrication and characterisation of photovoltaic device; O6) performances evaluation of optical sensor and photovoltaic device based on SiGeSn ncs. By implementing these objectives, the project brings original and novel results beyond the state of the art.

The project has scientific and technological impact (elucidating ncs formation in ternary alloys, photogeneration and collection of electric charges; fabricating devices with targeted parameters), economic and social impact (less expensive and eco-friendly technologies for large scale production of optelectric devices; formation of PhD students in project field). The project results will be published in 5 ISI papers and in 1 patent application.

Equipments from the infrastructure of National Institute of Materials Physics will be used for project implementation.

Project leader has important contributions in the scientific and technological fields directly related to the project topic, i.e. Nanostructured films, Photovoltaic devices and Nanoscale strain and its effect on electronic properties. Team members have relevant and complementary expertise in the project field.

Nano-Structured GeSn Coatings for Photonics Call name: P 3 - SP 3.2 - Proiecte ERA.NET
M.ERANET-3107-GESNAPHOTO 2016 - 2019

Role in this project: Key expert

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/projects/nano-structured-gesn-coatings-photonics-gesnaphoto

Abstract:

The objective of the project is manufacturing of nano-structured GeSn films for optical detection- emission in the short-wave infrared (SWIR) range (1-3µm). The novelty of the project consists in nano-structuring of layers containing GeSn in order to create GeSn nano-crystals with control of the size and Sn content, for obtaining high sensitivity. This material is a new group IV advanced coating material based on alloying Ge and Sn elements which extends the IR photonic range of Ge. The most important property is the transition into direct bandgap semiconductor for moderate Sn concentration, of critical importance for photonics of group IV semiconductors. Thus, the project deals with an alternative solution to the present III-V IR technology, a solution which is less expensive, environmentally friendly and compatible with Si technology. The IR detection-emission has many practical applications as for example night vision, medical applications, automotive, aviation, etc.

High photoconductive oxide films functionalized with GeSi nanoparticles for environmental applications Call name: P 3 - SP 3.2 - Proiecte ERA.NET
M-ERA.NET-PhotoNanoP 2016 - 2018

Role in this project: Key expert

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO); INSTITUTUL NATIONAL DE CERCETARE- DEZVOLTARE PENTRU MICROTEHNOLOGIE - IMT BUCURESTI INCD (RO); OPTOELECTRONICA - 2001 S.A. (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/projects/PhotoNanoP

Abstract:

A new solution for obtaining a new advanced material (SiO2, TiO2 films functionalized with GexSi1-x nanoparticles) with targeted photoconductive properties in VIS-NIR is proposed. This material is able to spectrally discriminate between dry, wet and icy asphalt, for reducing traffic accidents. The proposed approach and material are innovative, and technological and scientific results are original, leading to 1 patent application, 3 ISI and 4 conference papers. The project creates the frame for increasing EU cooperation, developing a pan-EU partnership between 2 research institutes, a university and 2 SMEs. Each partner will gain an advanced position in own activity field becoming more visible at EU and international level. All partners will have economic benefits by winning competitive advance in photodetector market and scientific benefits. The new material is versatile as PHC properties can be tuned leading to other environmental, biomedical, food and optosecurity applications.

Photo-Electric Capacitor Memory based on Ge-Nanocrystals Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2016-0286 2017 - 2018

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/PhotoElCaNanoMem

Abstract:

The main goal of the project is the fabrication of photo-electric Ge nanocrystals-based memories for eco-nanotechnology applications, combining an optical sensor with a non-volatile electronic memory in a single new device. In such device, both the electric field and the light can control the charge injection into the Ge nanocrystals (NCs) and thus the memory states of the device. It may work as a photo-electric sensor floating-gate memory, or a photo-electro switch floating-gate memory for event detection reversible device, with applications to security systems, intelligent home systems, integrated silicon photonics, etc. The used materials and fabrication technology are eco-friendly and compatible with silicon technology. In this project, the demonstrator is designed as a transparent electrode-oxide-semiconductor (MOS-type) capacitor memory with Ge-NCs in oxide matrix, NCs being coupled to the Si-substrate through a thin tunnel oxide. The active layers will be fabricated by magnetron sputtering deposition followed by rapid thermal annealing. The charge exchange between the substrate and the Ge-NCs can be controlled by electric field applied between the substrate and a gate (top) contact. At intermediary voltages, the capacitance-voltage characteristic shows hysteresis. The charge retention can be optimized for long term or dynamic memory. For top-illuminated demonstrator proposed by this project, a transparent electrode will be used and the retention dynamic will be optimised for photo-electric control of charge storage. The device operation is based on the generation of electrons and holes pairs under illumination and by this activation of the tunnelling process resulting in changes of the hysteresis states. The novelty of the proposed project consists in realization of a photo-sensitive Ge-NCs floating gate memory, tuning the structure of the demonstrator in order to obtain simultaneously electrical and optical control of the memory effect.

Si, Ge nanocrystals based dosimeter capacitor Call name: P 2 - SP 2.1 - Proiect experimental - demonstrativ
PN-III-P2-2.1-PED-2016-0206 2017 - 2018

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Project partners: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/projects/si-ge-nanocrystals-based-dosimeter-capacitor

Abstract:

The project proposes a new solution of MOS dosimeter, as a capacitor with a structure oxide/Ge or Si ncs layer/oxide/Si wafer with top and bottom metallic contacts, and oxide SiO2 or HfO2. It is aimed to be used as a radiation sensor in space or for medical applications. The proposed device is innovative as the approach is innovative by selecting oxide (SiO2 or HfO2) and (Si or Ge) nanocrystals to be embedded in, by modifying morphology and structure of the layer containing nanocrystals and in turn changing the deposition and annealing parameters and the thicknesses and stoichiometry of oxides. The feed-back between preparation and characterisation activities is used to maximize the sensitivity to the irradiation dose and the retention time. To prove the concept of the project, a demonstrator of the MOS capacitor-like dosimeter will be manufactured, and validated in laboratory environment, according to TRL3.

The specific objectives of the project are: deposition of Ge/oxide and Si/oxide, with oxide SiO2 or HfO2; nanocrystals formation by annealing; correlation of technological parameters with film structure and mor¬phology at different stages; manufacturing test samples of trilayer structures with metallic contacts, and testing them for the response to radiation; selection of structures with best response to radiation; validation of the innovative project concept by manufacturing a demonstrator based on trilayer structures with best response to radiation and retention time; testing the demonstrator according to TRL3;  dissemination and exploitation of the technological and scientific results (patent application, ISI and conference papers) taking into account IPRs;  coordination of activities in order to achieve all project objec¬tives, progress monitoring; continuity of information flow during project unfolding.

By accom¬plishing all these objectives, the outcome of the project, a new MOS capacitor for dose measurement as demonstrator, is obtained.

Novel nanostructured semiconductor materials based on Ge nanoparticles in different oxides for aplications in VIS-NIR photodetectors and nonvolatile memory devices Call name: Joint Applied Research Projects - PCCA-2011 call, Type 2
PN-II-PT-PCCA-2011-3.2-1120 2012 - 2016

Role in this project:

Coordinating institution: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA

Affiliation: INSTITUTUL NATIONAL DE CERCETARE - DEZVOLTARE PENTRU FIZICA MATERIALELOR BUCURESTI RA (RO)

Project website: http://www.infim.ro/ro/NODE/3960

Abstract:

The primary aim is to obtain novel nanostructured semiconductor materials based on Ge nanoparticles (nps) with optimized properties to be used in photodetectors for the visible and infrared (VIS-NIR) ranges, and also in nonvolatile (NV) memory devices. This aim will be realized in the following objectives: A) Preparation and characterization of nanostructured films based on Ge nps in SiO2, TiO2, HfO2, with optimized photoconductive and electrical properties; B) Preparation and complex characterization of experimental models for VIS-NIR photodetector and NV memory using the optimized materials; C) Fabrication of VIS-NIR photodetector and NV memory to prove experimentally the concepts of the project and its applications; D) Estimation of the economic impact.

Based on the material research (Phase 1), and on the investigations of structures and experimental models (Phase 2), two prototypes will be fabricated in Phase 3, one for the VIS-NIR photodetector, and one for the NV memory, with corresponding technical specifications. Thus, we will prove that the novel nanostructured materials based on Ge nps obtained in this project are suitable for VIS-NIR photodetectors and NV memory devices. Also, the technical and economical analyses documentation and feasibility studies will be performed (Phase 4).

The two devices will be integrated into a system for event identification and an automated test and measurement system for industrial applications and manufacturing devices will be realized.

The results obtained by achieving the project objectives have a high level of originality and novelty. Therefore, the scientific results will be promoted in 5 papers in peer-reviewed journals, and in 7 communications at prestigious international conferences. The technological results will be the object of 3 patent applications.

Young students will be involved in the project, and this will have a formative effect (Master Dissertations and/or PhD theses).

Surface and Interface Science: Physics, chemistry, biology, applications. Call name: Complex Exploratory Research Projects - PCCE-2008 call
PN-II-ID-PCCE-2008-0076 2010 - 2013

Role in this project:

Coordinating institution: INSATITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA MATERIALELOR

Project partners: INSATITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA MATERIALELOR (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU INGINERIE ELECTRICA (RO); UNIVERSITATEA DE MEDICINA SI FARMACIE CAROL DAVILA DIN BUCURESTI (RO); UNIVERSITATEA ALEXANDRU IOAN CUZA DIN IASI (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA TEHNICA DIN IASI (RO); INSTITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU TEHNOLOGII IZOTOPICE SI MOLECULARE DIN CLUJ-NAPOCA (RO); UNIVERSITATEA BABES-BOLYAI DIN CLUJ-NAPOCA (RO); ACADEMIA ROMANA FILIALA TIMISOARA (RO); UNIVERSITATEA DE MEDICINA SI FARMACIE VICTOR BABES TIMISOARA (RO)

Affiliation: INSATITUTUL NATIONAL DE CERCETARE DEZVOLTARE PENTRU FIZICA MATERIALELOR (RO)

Project website: http://www.infim.ro/projects/siinta-suprafetelor-si-interfetelor-fizica-chimie-biologie-aplicatii

Abstract:

This project intends to provide a financial background for developing the community of Surface Science in Romania. Thematics from physics and chemistry of surfaces will be tackled together with applications of surface science in biology and in technology; also new standards will be proposed for consistent data interpretation. The Project clusterizes the most important Romanian teams with preoccupations in surface science, namely all X-ray photoelectron spectroscopy teams with most of the community of thin film deposition, cluster and nanoparticle physics, surface reactivity, surface chemistry and photochemistry, multilayer physics and applications, magnetic fluids, functionalization of surfaces, cell attachment, studies of cellular membrane. The research teams belong to highly prominent Universities and Research Institutes from practically all geographical areas of the country. The Consortium disposes of infrastructure exceeding 10 million euros, of more than one hundreed highly qualified scientists which have generated during the past years more than 3 % of the national scientific visibility. The research will concentrate into four main areas: (i) magnetic properties of surfaces and low-dimensional systems; (ii) electrical properties of surfaces and heterostructures; (iii) surface chemistry; (iv) application of surface science in functionalized systems and in biology, together with (v) an area concentrating on standardization in X-ray photoelectron spectroscopy, Auger electron spectroscopy and related techniques. Each area is divided into several thematics; each thematic has at least one in-charge scientist. This Project will foster the surface science community in Romania and will contribute strongly to the development of high-technological industrial preoccupation in all geographical areas concerned. Several cutting-edge applications are also foreseen by pursuing the fundamental research proposed.

FILE DESCRIPTION	DOCUMENT
List of research grants as project coordinator or partner team leader
Significant R&D projects for enterprises, as project manager
R&D activities in enterprises
Peer-review activity for international programs/projects