Category Archives: New Functional Materials

Objavljen rad u časopisu Applied Surface Science te prijavljen patent

  Friday February 26th, 2021

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Znanstvenici Laboratorija za molekulsku fiziku i sinteze novih materijala IRB-a, doktorand Vlatko Gašparić mag. phys., dr. sc. Davor Ristić, dr. sc. Hrvoje Gebavi i dr. sc. Mile Ivanda objavili su u prestižnom časopisu Applied Surface Science (IF: 6.182) rad pod naslovom “Resolution and signal enhancement of Raman mapping by photonic nanojet of a microsphere”.

Fizičari objavili rad u časopisu Applied Surface Science te prijavili patent

U radu se po prvi puta primijenilo svojstvo tzv. fotonskog nanomlaza za pojačanje rezolucije i signala mapiranja u Ramanovoj spektroskopiji pomoću mehanički učvršćene mikrosfere, a konstruirana izvedba učvršćene mikrosfere prijavljena je i kao patent.

Ramanova spektroskopija nezaobilazna je metoda karakterizacije tvari u laboratoriju i na terenu, no zbog malog udarnog presjeka Ramanovog raspršenja, odziv je vrlo slabog intenziteta. Stoga su razvijene brojne metode pojačanja ove spektroskopske tehnike, od kojih je među najnovijima metoda koja koristi fotonski nanomlaz mikrosfere.

Fotonski nanomlaz (photonic nanojet – PNJ) izrazito je uzak i intenzivan snop svjetlosti koji nastaje uslijed obasjavanja dielektrične mikrosfere laserskim snopom ili ravnim valom svjetlosti. PNJ je zadobio pozornost znanstvenika od 2004. godine i našao je primjenu u raznim područjima. Da bi se iskoristio kao metoda pojačanja Ramanovog raspršenja pod mikroskopom, mikrosfere odgovarajućeg materijala i veličine potrebno je dovesti na površinu uzorka koji se istražuje te fokusirati upadni laserski snop iz mikroskopskog objektiva odgovarajuće širine i valne duljine kroz mikrosferu na uzorak.

Mikrosfere se deponiraju na uzorak kapanjem na podlogu, čime se njihove lokacije ne mogu kontrolirati. Međutim, na taj način moguće je prikupiti spektre samo izoliranih lokacija uzorka točno ispod mikrosfera.

Rad fizičara predstavlja novi pristup i izvedbeno rješenje u kontroliranju lokacije mikrosfere, na način da se mikrosfera pričvrsti na vrh stanjenog optičkog vlakna koje je stabilizirano drugim, okomito pričvršćenim stanjenim vlaknom, a pozicija se regulira mikropozicijskim podijima.

doktorand Vlatko Gašparić mag. phys., dr. sc. Davor Ristić, dr. sc. Hrvoje Gebavi i dr. sc. Mile Ivanda

doktorand Vlatko Gašparić mag. phys., dr. sc. Davor Ristić, dr. sc. Hrvoje Gebavi i dr. sc. Mile Ivanda

Inovacija je nazvana Two stemmed microsphere (TSMS). Korištenjem učvršćenja mikrosfere TSMS izvedbom, izbjegava se onečišćenje uzorka kapanjem tisuća mikrosfera, a mikrosferu je moguće dovesti na bilo koje mjesto na uzorku te održati pod upadnim snopom dok se uzorak pomiče. Drugim riječima, omogućuje se korištenje pojačanja fotonskog nanomlaza za ramansko mapiranje.

Rezultati istraživanja pokazali su tri puta bolju rezoluciju mapiranih površina, te četiri puta jači intenzitet signala spektara korištenjem TSMS-a s kvarcnom mikrosferom promjera 5 µm, u odnosu na isti eksperimentalni postav bez učvršćene mikrosfere. Eksperimentalna saznanja podržana su analitičkim simulacijama, za što su autori razvili računalni program na temelju Generalizirane Lorenz-Mie teorije upada laserske gausijanske zrake na mikrosferu. TSMS inovacija, te povezane varijante kontroliranja mikrosfere, prijavljene su i kao patent Državnom zavodu za intelektualno vlasništvo Republike Hrvatske.

Navedeni rezultati otvorili su novi put na području mapiranja u Ramanovoj spektroskopiji, čime je stvoren temelj za daljnje usavršavanje i usvajanje TSMS inovacije, kao i drugih inovacija za kontroliranje mikrosfere i upotrebe fotonskog nanomlaza.

Direct photo-capacitive neurostimulation using organic pigments

  Thursday May 3rd, 2018 ,

Localized stimulation of neurons in a safe and effective way is important for both research and therapeutic purposes. The currently available solutions based on micro- and nano-electrodes as well as on ion delivery platforms for neuronal electrical communications led to bioelectronic therapies and opened a new window of research in neuroscience. An important limitation of this approach is the need for wiring the electrode at the site of neurostimulation. The motivation for wireless access to the stimulation site has led to optogenic approaches, necessitating genetically modified  targeted neurons for the expression of light sensitive ion channels. Conventional approaches to addressing the wireless connectivity problem that does not include genetic modification include photoelectric stimulation in which the silicon solar cell of micrometric dimensions is attached to the neuronal excitation electrodes. These solutions are used in clinical applications as artificial retinas that are implanted into blind patients with damaged photoreceptors in the retina.

Electric field distribution arround the electrode for direct photocapacitive stimulation a) and d) made of b) organic pigments of p-type (H2PC) and n-type (PTCDI). c) Energy diagram of the electrode, e) schematic representation of the electrode operation.

A new approach to electrical stimulation of neurons comes from the Organic Electronics Laboratory from the University of Linköping in Sweden. Scientists in the group of prof.dr. Eric Glowacki, in which CEMS member Vedran Đerek participated as a post-doctoral student, presented a new approach to photoelectric stimulation of neurons using thin layers of organic semiconductors – cheap pigments used in cosmetics and the color industry (Advanced Materials, https: //doi.org/10.1002/adma.201707292). These pigments represent a class of new functional materials that are stable under physiological conditions, so they do not need to be protected from water encapsulation influence. The nature of the stimulus is completely capacitive, meaning that active materials – pigments – do not participate in chemical reactions during stimulation, therefore the device is persistent and can not introduce harmful substances into the body. The working principle was demonstrated by associates from prof.dr. Hanein group from Israel on the model of blind chicken retina, where in-vitro neurostimulation of retina neurons was demonstrated.

The Robin Hood Solver software package was used to calculate the three-dimensional distribution of electric potential around the photo-capacitive excitation electrode, which was provided by one of the authors of the package, dr. Predrag Lazić from IRB. The successful advancement of CEMS in the bioelectronic direction with the use of new functional materials can be a motivation for future research in which it would be possible to use the previously developed and explored materials within the framework of CEMS.

Foto: Thor Balkhed, LiU
Illustration source: https://doi.org/10.1002/adma.201707292

[SEMINAR] Glass based structures fabricated by rf-sputtering

  Friday May 26th, 2017

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Dr. Alessandro Chiasera (Consiglio Nazionale delle Ricerche – Istituto di Fotonica e Nanotechologie) će održati predavanje naslova: “Strukture na bazi stakla proizvedene pomoću Rf-sputteringa”. Predavanje će obuhvaćati opis proizvodnje jednodimenzionalnih fotoničkih kristala pomoću rf-sputteringa te njihovu karakterizaciju u vidu prostorno ovisne luminiscencije navedenih fotoničkih struktura i njihova lasiranja. Predavanje će biti održano u dvorani “Ivan Supek” u prvom krilu IRB-a u utorak 30.5.2017 u 12h 30 min.

 

[SEMINAR] Kemijska pohrana vodika u kondenziranoj materiji

  Tuesday November 8th, 2016

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Pozivamo Vas na predavanje dr.sc. Nikole Biliškova naslova “Kemijska pohrana vodika u kondenziranoj materiji” u srijedu 9.11.2016. u 14 sati u predavaonici I krila IRB-a.

Vodik se kroz zadnjih nekoliko desetljeća razmatra kao efikasan nosilac energije, koji bi unaprijedio efikasnost obnovljivih izvora energije. No, konvencionalnom pohranom vodika u plinskoj i tekućoj fazi osigurava se samo vrlo ograničeni sadržaj energije. Zato se razvija koncept kemisorpcijske pohrane u kondenziranoj materiji kao najefikasniji način pohrane vodika. Poteškoće povezane s razvojem takvih sustava za pohranu vodika učinile su tu problematiku jednom od ključnih suvremenih znanstvenih i tehnoloških izazova pri realizaciji široke upotrebe vodika kao nosača energije u bezugljičnoj „vodikovoj ekonomiji“. Iako je taj problem uglavnom kemijske naravi, pronalazak efikasnih sustava, koji zadovoljavaju sve zacrtane tehnološke potrebe, zahtijeva interdisciplinarni pristup.
Predavač će dati pregled dosadašnjih istraživanja na tom polju, koja se provode u Laboratoriju za kemiju čvrstog stanja i kompleksnih spojeva u kontekstu međunarodnih trendova na tom polju, uz naročit naglasak na najnovije rezultate. Također, bit će izneseni i planovi za budućnost, koji su se dijelom već počeli realizirati.

Priopcenje za javnost povodom opstruiranja financiranja iz EU fondova od strane MZOS-a

  Wednesday June 8th, 2016 , , ,

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PRIOPĆENJE ZA JAVNOST – Zagreb, 7. lipnja 2016.

Otvoreno pismo ministru znanosti, obrazovanja i sporta Predragu Šustaru:

‘‘Opstruiranjem financiranja iz EU fondova hrvatskih znanstvenih centara izvrsnosti ugrožava se 50 milijuna eura iz strukturnih fondova i radna mjesta za hrvatske znanstvenike – traži se hitna reakcija ministra Šustara!‘‘

Pedeset milijuna eura, upitna radna mjesta za čak tri stotine doktoranada i postdoktoranada, te riskiranje penala od Europske komisije, samo su dio crne statistike koja ozbiljno prijeti Republici Hrvatskoj (RH), a odvija se u sjeni problema s kurikularnom reformom.

Deset znanstvenih centara izvrsnosti proglašenih od strane Ministarstva znanosti obrazovanje i sporta (MZOS) tijekom 2014. i 2015. godine na prijedlog Nacionalnog vijeća za znanost, visoko obrazovanje i tehnološki razvoj, posljednjih su nekoliko mjeseci postalo taocem MZOS-a.

Naime, RH se strateški odredila kroz Operativni program (OP) za financiranje Znanstvenih centara izvrsnosti (2014 – 2020), te se prema Operativnom programu očekuje 50 milijuna eura iz Europskog fonda za regionalni razvoj (ERDF) koji bi bili na raspolaganju proglašenim centrima.

Kako bi centri mogli iskoristiti europska sredstva, MZOS je obvezan raspisati natječaj. Prvi indikativni rok za raspisivanje natječaja bio je 31. ožujka, te je pomaknut na 1. lipnja 2016., a natječaj još nije raspisan.

Unatoč brojnim službenim molbama za poštivanjem obveza koje su voditelji Znanstvenih centara izvrsnosti posljednjih mjeseci dostavili ministru Šustaru i premijeru Oreškoviću s upozorenjem da je RH preuzela obvezu te je dužna raspisati planirani natječaj iz strukturnih fondova u sklopu kojih bi se izvršila evaluacija planiranih troškova u okviru pojedinih centara, s današnjim datumom MZOS još uvijek nije aktivirao natječaj Europskog fonda za regionalni razvoj (ERDF) koji bi omogućio povlačenje čak 50 milijuna eura za Znanstvene centre izvrsnosti. Time se ozbiljno ugrožava realizacija znanstvenih aktivnosti proglašenih ZCI-a i gubitak 50 milijuna eura iz EU te zapošljavanje 300 mladih stručnjaka.

Podsjetimo, MZOS je proglasio Znanstvene centre izvrsnosti iz područja prirodnih, biomedicinskih, biotehničkih i tehničkih znanosti nakon zahtjevnih kriterija javnog natječaja, uključujući opsežne domaće i međunarodne recenzije i intervjue s voditeljima predloženih centara koji su proveli Agencija za znanost i visoko obrazovanje (AZVO) i Nacionalno vijeće za znanost, visoko obrazovanje i tehnološki razvoj. MZOS je potom temeljem članka 29. stavka 2. Zakona o znanstvenoj djelatnosti i visokom obrazovanju (Narodne novine, broj: 123/2003, 105/2004, 174/2004, 2/2007 – Odluka Ustavnog suda Republike Hrvatske, 46/2007, 45/2009,63/2011,94/2013, 139/13 i 101/2014 – Odluka i Rješenje Ustavnog suda Republike Hrvatske) proglasilo znanstvene centre izvrsnosti RH, čiji su članovi izvrsni hrvatski znanstvenici, među nositeljima međunarodne prepoznatljivosti hrvatske znanosti.

Proces prijave, vrednovanja i odabira centara trajao je tri godine, a Vlada RH je nakon provedenog postupka recenzija uskladila program centara s nacionalnim prioritetima i oni su u skladu sa Strategijom pametne specijalizacije (S3). Ovu Strategiju su više od dvije godine izrađivali brojni eksperti iz javnog i privatnog sektora koji se bave istraživanjem i razvojem, te ju je usvojio Hrvatski sabor i Europska komisija za znanost.

Cilj proglašenja centara je bio omogućiti izvrsnim hrvatskim znanstvenicima i institucijama uvjete za vrhunski istraživački rad kroz stabilno i pojačano financiranje te edukaciju mladih znanstvenika i značajan doprinos gospodarstvu RH.

Slijedom navedenog, proizlazi da se nepoštivanjem zadanih obveza od strane MZOS-a te neprovođenjem preuzetih obveza direktno ugrožavaju nacionalni interesi.

Nažalost, jedan od glavnih protivnika ustroja hrvatskih centara izvrsnosti, kao i od strane Europske komisije usvojene pametne specijalizacije (S3) RH, a koja je jedan od glavnih preduvjeta za povlačenje sredstava iz strukturnih fondova, je pomoćnik ministra za znanost dr. sc. Krešimir Zadro.

Poštovani ministre Šustar, otvorenim pismom javnosti obraćamo Vam se ispred svih Znanstvenih centara izvrsnosti (ZCI) iz područja prirodnih, biomedicinskih, biotehničkih i tehničkih znanosti sa zahtjevom da se javno očitujete o razlozima nepoštivanja odluka Vlade RH i neprovođenju usvojenih programa financiranja hrvatskih centara izvrsnosti iz EU fondova te datumu raspisivanja natječaja kako bi se izbjegao crni scenarij.

Vjerujemo da niste spremni potpuno ignorirati izvrsne hrvatske znanstvene skupine i propustiti priliku da se kroz usvojeni program pametne specijalizacije povuku sredstva u iznosu od 50 milijuna eura iz strukturnih fondova.

U situaciji kad se domaća sredstva za znanost i istraživanje sustavno režu, kad se događa egzodus najboljih mladih obrazovanih stručnjaka, znanstvena istraživanja i inovacije preživljavaju velikim dijelom zbog izvrsnosti istraživačkih skupina i velikih napora znanstvenika u povlačenju sredstva iz programa Europske unije, ovakvo opstruiranje rada Znanstvenih centara izvrsnosti da osiguraju europska sredstva za rad i zapošljavanje stručnog kadra je nedopustivo!

S poštovanjem,
voditelji proglašenih Znanstvenih centara izvrsnosti (STEM područja):

Znanstveni centar izvrsnosti za napredne materijale i senzore,
Institut Ruđer Bošković i Institut za fiziku, Zagreb

Dr. sc. Milko Jakšić – Milko.Jaksic@irb.hr
Dr. sc. Mile Ivanda – Mile.Ivanda@irb.hr
Dr. sc. Mario Stipčević – Mario.Stipcevic@irb.hr
Dr. sc. Marko Kralj – mkralj@ifs.hr

Znanstveni centar izvrsnosti za reproduktivnu i regenerativnu medicinu,

Medicinski fakultet, Sveučilište u Zagrebu,
Akademik prof. dr.sc. Slobodan Vukičević – slobodan.vukicevic@mef.hr
Prof. dr. sc. Davor Ježek – davor.jezek@mef.hr

Znanstveni centar izvrsnosti za virusnu imunologiju i cjepiva,
Medicinski fakultet, Sveučilište u Rijeci
Prof. dr. sc. Stipan Jonjić – stipan.jonjic@medri.uniri.hr

Znanstveni centar izvrsnosti za znanost i tehnologiju – STIM, Sveučilište u Splitu
Prof. dr. dr. h.c. Vlasta Bonačić-Koutecky – vbk@cms.hu-berlin.de

Znanstveni centar izvrsnosti za bioraznolikost i molekularno oplemenjivanje bilja, Agronomski fakultet , Sveučilište u Zagrebu
Prof. dr. sc. Zlatko Šatović – zsatovic@agr.hr

Znanstveni centar izvrsnosti za bioprospecting mora
Institut Ruđer Bošković, Zagreb
Dr.sc. Rozelindra Čož-Rakovac – Rozelindra.Coz-Rakovac@irb.hr

Znanstveni centar izvrsnosti za kvantne i kompleksne sustave te reprezentacije Liejevih algebri, Prirodoslovno-matematički fakultet, Sveučilište u Zagrebu

Prof.dr.sc Hrvoje Buljan – hbuljan@phy.hr
Prof. dr. sc. Pavle Pandžić – pandzic@math.hr

Znanstveni centar izvrsnosti za personaliziranu brigu o zdravlju,

Sveučilište Josip Juraj Strossmayer u Osijeku
Prof. dr. sc. Gordan Lauc – glauc@pharma.hr
Prof. dr. sc. Ines Drenjančević – ines.drenjancevic.peric@mefos.hr

Znanstveni centar izvrsnosti za temeljnu, kliničku i translacijsku neuroznanost, Medicinski fakultet, Sveučilište u Zagrebu
Prof. dr. sc. Miloš Judaš – mjudas@hiim.hr

Znanstveni centar izvrsnosti za znanost o podatcima i kooperativne sustave, Fakultet elektrotehnike i računarstva, Sveučilište u Zagrebu

Prof.dr.sc. Sven Lončarić – sven.loncaric@fer.hr
Prof. dr. sc. Ivan Petrović – ivan.petrovic@fer.hr

Priopćenje voditelja proglašenih
            Znanstvenih centara izvrsnosti (STEM područja)             ___________________________________________________________________________________________________

Acitivities

Predavanje 9.11.2016. dr.sc. Nikole Biliškova  “Kemijska pohrana vodika u kondenziranoj materiji”

Vodik se kroz zadnjih nekoliko desetljeća razmatra kao efikasan nosilac energije, koji bi unaprijedio efikasnost obnovljivih izvora energije. No, konvencionalnom pohranom vodika u plinskoj i tekućoj fazi osigurava se samo vrlo ograničeni sadržaj energije. Zato se razvija koncept kemisorpcijske pohrane u kondenziranoj materiji kao najefikasniji način pohrane vodika. Poteškoće povezane s razvojem takvih sustava za pohranu vodika učinile su tu problematiku jednom od ključnih suvremenih znanstvenih i tehnoloških izazova pri realizaciji široke upotrebe vodika kao nosača energije u bezugljičnoj „vodikovoj ekonomiji“. Iako je taj problem uglavnom kemijske naravi, pronalazak efikasnih sustava, koji zadovoljavaju sve zacrtane tehnološke potrebe, zahtijeva interdisciplinarni pristup.
20161109_140659 20161109_140711

 

Training School on Raman Spectroscopy at the Ruđer Bošković Institute organised under the  COST Action MP1302 – Nanospectroscopy, September 23-25, 2015

Presentation slides from the Training School on Raman Spectroscopy, from the tutorial lectures held during the Raman School are available here for the Raman School participants. The access password can be obtained from the Raman School organizers:

MP1302-Raman school_Baranovic
MP1302-Raman school_Derek
MP1302-Raman school_Ivanda_1
MP1302-Raman school_Ivanda_2
MP1302-Raman school_Kveder
MP1302-Raman school_Mikac
MP1302-Raman school_Mohacek-Grosev
MP1302-Raman school_Ristic
MP1302-Raman school_Skenderovic

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Projects

2015-2019 “Hybrid Silicon Nanostructures for Sensing”, Croatian Science Foundation, project no.: IP-2014-09-7046.

2014-2019 “New functional materials”, Center of excellence for new materials and sensors, Leader: M. Ivanda, Funding source: Ministry of Science and Technology of Croatia and the Structural Funds of European Union.

COST Training School on Raman Spectroscopy

  Friday September 18th, 2015

COSTCEMS-NFM is organizing the Training School on Raman Spectroscopy for the COST action “Nanospectroscopy” MP1302. The school will take place at the Ruder Boškovic Institute in Zagreb, Croatia, on September 23-25, 2015. Selected topics are historical introduction of the Raman spectroscopy, theory of Raman spectroscopy on molecules and crystals, surface enhanced Raman spectroscopy and applications, Raman spectroscopy of  nanoparticles, Raman scattering on disordered materials, Raman spectroscopy in materials research, Time-resolved techniques with ultrashort pulses in examination of specific vibrational states of matter, application of ESR spectroscopy in probing of vibrational states of disordered materials and practical laboratory courses on Raman spectroscopy. Guest speaker for the school is Prof. Philippe Colomban, UPMC Paris, with the topic “Raman Spectroscopy of advanced materials (fibre, composites, films, ..) for aerospace and energy application”. The preliminary program can be found here. The Training School aims particularly at Early-Stage Researchers. The number of participants for laboratory courses is limited to allow for hands-on training, but the lectures are open to the general public.

UPDATE: Presentation slides, from the tutorial lectures held during the Raman School are available here for the Raman School participants.

APL paper: Enhanced NIR response of nano-silicon/organic hybrid photodetectors

  Monday August 31st, 2015

Infrared photodetectors are a major component of many optoelectronic devices used in telecommunications, sensing, and imaging technologies. Long distance telecommunications are enabled by silica optical fibers, where near-infrared (NIR) wavelengths in the range of 1.3–1.6 m are used due to the superior transparency of silica in this range. Heterojunctions between an organic semiconductor and silicon are an attractive route to extending the response of silicon photodiodes into the NIR range, up to 2000 nm. Silicon-based alternatives are of interest to replace expensive low band-gap materials, like InGaAs, in telecommunications and imaging applications. Micro- and nano-structuring of silicon can significantly influence its properties, which can enable enhancement of silicon-based devices by careful nano-scale optimization.

Schematic representations of structured versus planar heterojunctions between silicon and a thin organic semiconductor epilayer

(a) Schematic representations of structured versus planar heterojunctions between silicon and a thin organic semiconductor epilayer. The upper row shows single-step structuring, while hierarchical combinations of different structuring techniques are on the second row. (b) Device schematic of an Al/p-Si/TyP/Al heterojunction device, with the molecular structure of TyP. (c) Band diagram of an Al/p-Si/TyP/Al heterojunction diode under short circuit conditions. The red arrow represents the sub-band gap NIR absorption.

The study “Enhanced near-infrared response of nano- and microstructured silicon/organic hybrid photodetectors“, published by journal Applied Physics Letters (IF 3.569) of the American Institute of Physics, is a result of collaboration of the research groups of prof. Niyazi Serdar Sariciftci, Institute for Organic Solar Cells (LIOS)/Physical Chemistry at the Johannes Kepler University in Linz, Austria and  of dr. Mile Ivanda from CEMS-NFM at Ruđer Bošković Institute in Zagreb, Croatia. The research work was performed by a 5-month visit of V. Đerek to LIOS, Linz and his close collaboration with the LIOS group member Eric Daniel Głowacki. The visit of V. Đerek was supported by the Ernst-Mach-Stipendien granted by the OeAD—Austrian Agency for International Cooperation in Education & Research, financed by BMWF.

The paper reports  on the significant enhancement in NIR photodetector performance afforded by nano- and microstructuring of p-doped silicon (p-Si) prior to deposition of a layer of the organic semiconductor Tyrian Purple (TyP). Heterojunction diodes with the general device structure as shown in Figure (b) were prepared with various nano- and microstructuring methods as shown in Figure (a), with planar devices always being prepared in parallel to provide an “internal” standard for a given set of measurements. A number of well-established techniques was employed to increase the interfacial area of the p-Si/organic junction, both alone and in hierarchical combinations: (1) micropyramids (μ-pyramids) with dimensions ∼10 m; (2) metal-assisted chemically etched (MACE) porous silicon with ∼50–200 nm pores; and (3) electrochemically anodized porous silicon, with pore sizes of 10–1000 nm. It was shown how different silicon structuring techniques, namely, electrochemically grown porous Si, metal-assisted chemical etching, and finally micropyramids produced by anisotropic chemical etching (Si μP), are effective in increasing the NIR responsivity of p-Si/TyPheterojunction diodes.

In all cases, the structured interfaces were found to give photodiodes with superior characteristics as compared with planar interface devices, providing up to 100-fold improvement in short-circuit photocurrent, corresponding with responsivity values of 1–5 mA/W in the range of 1.3–1.6 m. The measurements have shown that this increased performance is neither correlated to optical effects, i.e., light trapping, nor simply to geometric surface area increase by micro- and nanostructuring. The performance enhancement afforded by the structured p-Si/organic diodes is likely caused by a yet unresolved mechanism, possibly related to electric field enhancement near the sharp tips of the structured substrate. The observed responsivity of these devices places them closer to parity with other, well-established, Si-based NIR detection technologies.

The collaboration included a group members from CEMS-NFM, IRB, Zagreb (V. Đerek, M. Marcijuš, M. Ristić and M. Ivanda), from LIOS, Linz (E. D. Głowacki and N. S. Sariciftci) and from Friedrich-Alexander Universität, Energie Campus, Erlangen/Nürnberg (M. Sytnyk and W. Heiss).

SEM images of different nano- and microstructured Si surfaces with a 40-nm TyP epilayer evaporated on top. (a) Porous Si, (b) Si MACE, (c) Si μ-Pyramids, (d) hierarchical Si μ-pyramids/porous Si, (e) hierarchical Si μ-pyramids/MACE, and (f) hierarchical Si μ-pyramids/MACE/porous Si.

SEM images of different nano- and microstructured Si surfaces with a 40-nm TyP epilayer evaporated on top. (a) Porous Si, (b) Si MACE, (c) Si μ-Pyramids, (d) hierarchical Si μ-pyramids/porous Si, (e) hierarchical Si μ-pyramids/MACE, and (f) hierarchical Si μ-pyramids/MACE/porous Si

Research topics

The first goal of the proposed NFM is to stimulate research in advanced materials science and engineering through facilitation of inter-disciplinary and multi-disciplinary research groups of the Centre. The proposed researcher activities at NFM for each proposed area in the 5 yrs period is based on the synergetic effect of involved research groups/laboratories based on the focusing on the best existing research thematic as well as by opening of new hot research topics that promise fast developments of scientific excellences and new high technology products. The proposed enhancing of the cooperation of researchers within the Center will be focused within the following three research programmes: 

P1. Silicon nanostructures for advanced applications (leader M. Ivanda)

P2. Sol-gel technology for new functional materials   (leader M. Ristić)

P3. Nanostructural materials for energetic (leader N. Radić)

 

Within the first programme P1. Silicon nanostructures for advanced applications the research will be focused on nanostructural silicon thin films for advanced applications. The Low Pressure Chemical Vapor Deposition (LPCVD) and Physical Vapor Deposition (PVD) developed at Ivanda’s group will be used for deposition thin films and wires of silicon, silicon reach oxide, silicon reach nitride, amorphous silicon, polycrystalline silicon, doping with boron, phosphorus, erbium and europium on flat silicon, quartz glass and alumina substrates as well as on silica microspheres. The porous silicon will be prepared by anodisation process. The structural, optical, electrical and transport properties will be investigating. The research work will be carried out under following projects that will be leaded by M. Ivanda:

T1. Low dimensional silicon for chemical sensing,

T2. Silicon thermoelectric element

T3. Novel silicon based materials for photonics

 T4. Development of new Raman scattering techniques

Within the second programme P2. Sol-gel technology for new functional materials the research on the synthesis of diversity of nanocrystals and nanostructures and their possible applications will be performed. Mechanisms of the precipitation of metal oxides for sensing such as iron oxides and Me-doped iron oxides will be investigated. Novel metallic nanoparticles in the form of colloidal suspensions for biomedical applications will be synthesized and analysed. An apparatus for the synthesis of nanowires will be built. The green-chemistry routes will be used in the synthesis of metal oxide and metallic nanoparticles. Characterization of structural, particulate, and surface properties of the synthesized materials will be performed by well established techniques. The research work will be carried out under following projects:

T1. Nanocrystalline metal oxides for chemical sensing (leader M. Ristić)

T2. Nanoparticles for the use in medical application (leader M. Gotić)

T3. Low dimensional 1D and 2D metal oxides for new functional materials (leader M. Ristić)

T4. R&D of novel multiferroic materials (leader I. Đerđ)

The main goal of the third programme P3. Nanostructural materials for energetic is investigation of preparation, structural properties and application of nano-based materials prepared by magnetron sputtering deposition. The prime interest is investigation of recently invented materials based on self assembled nanoparticles in amorphous matrices. These materials are discovered and developed by our group in the recent few years. They consist of regularly ordered nano-objects of different composition (metallic, semiconductor, and mixed) embedded in various amorphous matrices (alumina, silica, mullite). These materials have a great potential for application in various nanotechnology fields. The most promising applications of semiconductor quantum dots are super-efficient solar cells and photodetectors. Metallic nanoparticles are of great interest for different, today very popular, spintronic applications. The mixed nanoparticles are expected to have some extraordinary properties like electric-field tuneable magnetic properties for the case of semiconductor-metallic mixture. Additional advantage of these materials is regular ordering of nanoparticles in them. It is well known that in such systems are expected some collective behaviour effects, which enable engineering and design of the materials opto-electrical properties. Additionally, our most-recent activities resulted in development of nanomaterials which show extraordinary capability to store hydrogen. These materials are of great interest for energy storage. The main objective of the programme is to become a Croatian center for preparation, characterization and application of these extraordinary nano-based materials. The activities of the programme will be realised under the 3 projects:

T1. Semiconductor quantum dots (leader M. Buljan)

T2. Metallic nanoparticles (leader N. Radić)

T3. Materials for hydrogen storage (leader N. Radić)