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:
-
Carmen TISEANU (Project Leader)
-
Bogdan COJOCARU (Senior Researcher)
-
Alin BROASCA (Msc Student)
- Claudiu COLBEA (Msc Student)
Project Annual Reports
(Romanian):
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:
Raport stiintific privind implementarea proiectului in perioada iulie 2017 - decembrie 2019
Project Synthetic Report (English)
Project Publications, Papers published in ISI journals
8. D. Avram, A. A. Patrascu, M. C. Istrate, B. Cojocaru, C. Tiseanu, "Lanthanide doped TiO2: Coexistence of discrete and continuous dopant distribution in anatase phase." Journal of Alloys and Compounds (2021), 851, 156849.
7. B. Cojocaru, C. Colbea, D. Avram, C. Istrate, L. Abramiuc, C. Tiseanu "Role of Ln type in the physical mechanisms of defect mediated luminescence of Li, Ln - SnO2 nanoparticles", Journal of Materials Chemistry C (2021),9, 148-157.
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)
