LABORATORY FOR SYNTHESIS and CRYSTALLOGRAPHY OF FUNCTIONAL MATERIALS
12/2019
Our new paper on perovskite LEDs is published in Advanced Optical Materials!
Ruddlesden–Popper halide perovskite (RPP) materials are of significant interest for light‐emitting devices since their emission wavelength can be controlled by tuning the number of layers n, resulting in improved spectral stability compared to mixed halide devices. However, RPP films typically contain phases with different n, and the low n phases tend to be unstable upon exposure to humidity, irradiation, and/or elevated temperature which hinders the achievement of pure blue emission from n = 2 films. In this work, two spacer cations are used to form an RPP film with mixed cation bilayer and high n = 2 phase purity, improved stability, and brighter light emission compared to a single spacer cation RPP. The stabilization of n = 2 phase is attributed to favorable formation energy, reduced strain, and reduced electron–phonon coupling compared to the RPP films with only one type of spacer cation. Using this approach, pure blue light‐emitting diodes (LEDs) with Commission Internationale de l'éclairage (CIE) coordinates of (0.156, 0.088) and excellent spectral stability are achieved.
11/2019
2DPEROEXLORE project meeting @ HKU
Team members J. Popovic and Z. Skoko visited Prof. A. Djurisic at HKU. Many discussions on a preliminary data resulted in detailed plan for the next period fully defined. Full force ahead!
11/2019
Laboratory for synthesis and crystallography of functional materials welcomes new member!
PhD student Juraj Ovčar joined our team. Juraj will be working together with Ivor and Luca on the theoretical calculations related to the structure of 2D perovskites.
Juraj welcome!
10/2019
Contract for our 2DPEROEXLORE project signed!
Contract between HKU and RBI is signed. Our 2DPEROEXLORE project has officially started! This project is fully supported by the “Research Cooperability“ Program of the Croatian Science Foundation funded by the European Union from the European Social Fund under the Operational Programme Efficient Human Resources 2014-2020.
10/2020
Our new paper in Sci. Rep. is out!
Inorganic materials that enable a link between the storage and release of molecular oxygen offer a fertile ground in continuous quest for the applications that can potentially reduce energy consumption and thus minimize adverse effects on the environment. Herein, we address reversible intake/release of an oxygen within the BaAl2O4 material as evidenced by unexpected magnetic ordering. Magnetic measurements unveil that an oxygen is stored in the form of condensed matter, creating a kind of low dimensional, chain-like assembly within the tunnels of BaAl2O4 structure. We demonstrate that oxygen is adsorbed simply by staying in air, at ambient conditions, and released relatively quickly by staying in the He or other gas atmosphere of several millibars pressure even at 300 K.
10/2019
Organization of HTCC4, Mlini, Croatia, Oct. 1 – 6, 2019
Over four intense working days, we coverd techniques which go beyond classical crystallography, yet which complement it so smoothly: XFEL – X-ray free electron laser, cryo electron microscopy and biomolecular in-silico simulations. Organization by Croatian Association of Crystallographers, chair: A. Višnjevac, co-chair: J. Popović
10/2019
Our Sanja obtained her PhD! Congratulations!!
Sanja obtained her PhD degree with thesis "Mechanochemical synthesis and structural characterization of bimetallic and hybrid tetrahydridoborates"
https://dr.nsk.hr/islandora/object/pmf%3A7533
We also had an excellent time celebrating with evaluation committee members: Prof. Radovan Cerny, Prof. Vladimir Stilinović and Dr. Marijana Jurić
09/2019
14th Multinational Congress on Microscopy
September 15-20, 2019 in Belgrade, Serbia
Attendance at MCM14. Invited lecture by Marijana Jurić. Charing session by Željko Skoko.
During our stay in Belgrade, we also performed optical measurements in the scope of collaboration with Prof. Aleksandra Dapčević at Faculty of Technology and Metallurgy, University of Belgrade.
06/2019
Plenary lecture at SCCM27,19-23 June 2019, Rogaška Slatina, Slovenia, given by Martina Vrankić
Plenary lecture at 27th Slovenian-Croatian crystallographic meeting held in Rogaška Slatina under title "Ambient and non-ambient driven X-ray powder diffraction: insights into the structure-property relationship in powders" presented by Martina Vrankić
06/2019
5th Conference of the Serbian Society for Ceramic Materials,
11th – 13th June, 2019, Belgrade, Serbia
At I5th Conference of the Serbian Society for Ceramic Materials J. Popović presented an invited lecture: "Rational design of hybrid perovskites"
J. Popović was also a member of International Advisory Board.
05/2019
First paper from PhD thesis of Sanja published in Inorganic Chemistry. Congrats Sanja!
The first bimetallic imidazolates containing alkali and alkaline earth metals, NaMgIm3 and KMgIm3, respectively, are prepared by mechanochemical synthesis and are reported in this paper. NaMgIm3 has been prepared by the reaction between NaIm and Mg(BH4)2 as well as directly from NaIm and MgIm2. Structural evolution and thermal stability were followed by an in situ high-temperature X-ray powder diffraction experiment utilizing synchrotron radiation. In both compounds, the imidazolate ligand is connected to four metal cations forming a complex three-dimensional network with channels running along the c-direction. NaMgIm3 and KMgIm3 are the first members of a new family of imidazolate frameworks with stp topology. The formation of mixed-alkali-metal imidazolate compounds is thermodynamically controlled. LiIm and MgIm2 have not yielded a mixed-metal compound, while KIm reacts swiftly and forms KMgIm3.
05/2019
Visit to Dept. of Civil, Environmental and Mechanical Engineering, Università di Trento, Italija
Invited lecture in the scope of collaboration with prof. dr. Paolo Scardi. J. Popović delivered a lecture under the title "2D and quasi 2D perovskites".
J. Popovic was also a member of evaluation committee for PhD thesis defense of Alberto Flor.
04/2019
26th Croatian meeting of chemists and chemical engineers, Šibenik, Croatia, 08-12 April 2019
At 26th Croatian meeting of chemists and chemical engineers, J. Popović presented an invited lecture under the title "From rational structural design to enhanced efficiency and stability of novel LED materials".
Our PhD student Sanja Burazer gave an excellent lecture about novel mixed imidazolate structures under the title "Mechanochemical synthesis and crystal structure of new group of mixed–metal imidazolates AMgIm3"