Project Title:             Doped oxide nanoparticles: From local structure to long – range perspective via luminescence

Project Code:            PN-III-P4-ID-PCE- 2016-0305

Contract Nr. :            67/2017

Project Funded by:  UEFISCDI, Ministry of Education, Research, Youth and Sport, Romania 

Period:                       2017 - 2019

Project Leader:        Carmen TISEANU

Contract Value:        850.000 RON


Project Summary  

       In the case of aliovalent doping, the misfit in the valence but also the ionic radii of the bulkier Ln dopants and host cations can lead to a complex distribution of Ln as isolated substitutional /interstitial centres or associates with defects (arising via charge – compensation) and reduced solubility. So, the first question to be answered when studying lanthanide doped nanoparticles (NPs) is the following: How do we know if the nanoparticles have been successfully doped? To tackle this issue, we should turn to a powerful local structure technique. Since the dopants class is represented by the optically active Ln ions, a “natural” selection would be the luminescence spectroscopy based on use of Ln as luminescence probes. The project aims at clarifying the local structure around Ln dopants in three outstanding wide bandgap oxides SnO2, TiO2 and HfO2. As Ln dopants with local probe properties, we select the Eu, Sm, Tb, Dy and Er ions with relevant emission in the visible and near – infrared, respectively. Our luminescence based on the simultaneous analysis of the site selective and time-gated luminescence allows an exceptional insight into the photophysics of doped NPs. The project will address also the current limitations existing in the literature and which regard, essentially, the correlation between the local structure and long - range properties. To this aim, we will correlate the in situ luminescence with in situ X – ray diffraction and in situ Raman data to get in depth insight into the order/disorder, doping and surface effects during amorphous /crystalline to crystalline phase transition.
We believe that our luminescence based approach centred on the local structure analysis will give a better perspective on how to tackle the issue of doping Ln ions in wide bandgap oxide NPs and beyond. Integrating local and long – range information into a unitary description of lanthanide doped nanoparticles via luminescence is certainly relevant for the vast majority of the lanthanide doped nanostructures. Since single or multiple functionalities of the oxide NPs are generally enhanced by the substitutional Ln doping, a more general understanding of the relationship between dopant − oxide and the desired property or application can be established. From the fundamental research side, the project is expected to enlarge our understanding of magnetic dipole emission of Ln ions.


Project Objectives:

The project aims at clarifying the local structure around lanthanide dopants in three outstanding wide bandgap oxides SnO2, TiO2 and HfO2. Our luminescence approach based on the simultaneous analysis of the site selective and time-gated luminescence allows an exceptional insight into the photophysics of doped nanoparticles. The project will address also the current limitations existing in the literature and which regard, essentially, the correlation between the local structure and long - range properties.


Project Team:


Project Annual Reports (Romanian):

Stage 2017:

Contract Value: 318.750,00 RON

Raport stiintific privind implementarea proiectului in perioada iulie 2017 - decembrie 2017


Stage 2018:

Contract Value: 227.802,00 RON
Raport stiintific privind implementarea proiectului in perioada ianuarie 2018 - decembrie 2018


Stage 2019:

Contract Value: 303.448,00 RON
Raport stiintific privind implementarea proiectului in perioada
iulie 2017 - decembrie 2019

Project Synthetic Report (English)


Project Publications, Papers published in ISI journals

1. B. Cojocaru, D. Avram, V. Kessler, V. Parvulescu, G. Seisenbaeva, C. Tiseanu "Nanoscale insights into doping behavior, particle size and surface effects in trivalent metal doped SnO2" Sci. Rep. 7(1) 9598 (2017) (2018 IF = 4.525)

2. M. Florea, D. Avram, V. A. Maraloiu, B. Cojocaru, C. Tiseanu "Heavy doping ceria by wet impregnation: A viable alternative to bulk doping approaches" Nanoscale, (2018),10, 18043-18054 (2018 IF= 6.97).

3. C. Colbea, D. Avram, B. Cojocaru, R. Negrea, C. Ghica, V. Kessler, G. Seisenbaeva, V. Parvulescu, C. Tiseanu "Full tetragonal phase stabilization in ZrO2 nanoparticles by wet impregnation: Interplay of host structure, dopant concentration and sensitivity of characterization technique", Nanomaterials, (2018), 8(12), 988 (2018 IF= 4.034).

4. B. Cojocaru, D. Avram, R. Negrea, C. Ghica, V. G. Kessler, G. A. Seisenbaeva,  V. I. Parvulescu, C. Tiseanu "Phase Control in Hafnia: New Synthesis Approach and Convergence of Average and Local Structure Properties." ACS Omega, (2019) 4(5), 8881-8891.

5. D. Avram, C. Colbea, M. Florea, S. Lazar, D. Stroppa, C. Tiseanu "Imaging dopant distribution across complete phase transformation by TEM and upconversion emission" Nanoscale, (2019), 10, 18043-18054 (2018 IF= 6.97). (The article is presented on the front cover of the Nanoscale Volume 11 Issue 36)