Vol.:(0123456789) 1 3
Journal of Materials Science: Materials in Electronics
https://doi.org/10.1007/s10854-020-03930-6
REVIEW
A review on recent progress in rare earth and transition metals
activated SrY
2
O
4
phosphors
Ruby Priya
1
· Sandeep Kaur
1
· Utkarsh Sharma
1
· O. P. Pandey
1
· Sanjay J. Dhoble
2
Received: 30 April 2020 / Accepted: 1 July 2020
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract
SrY
2
O
4
belongs to the family of AB
2
O
4
(A = alkaline earth metal, B = rare earth element) type spinel oxides. SrY
2
O
4
is an
inter oxide in SrO and Y
2
O
3
pseudo-binary phase diagram. It has attracted immense interest as a promising host lattice owing
to its thermal and chemical stability. The luminescent characteristics of SrY
2
O
4
phosphors make them promising candidates
for feld emission displays. In the present review article, recent progress in the synthesis and luminescent properties of bare
and doped SrY
2
O
4
phosphors are reviewed. In the frst part, diferent synthesis routes and their resultant outcomes are dis-
cussed. Then, the downconversion and upconversion luminescent characteristics of undoped and doped SrY
2
O
4
phosphors are
reviewed. The efect of site occupancy, morphology, reaction conditions, diferent excitation wavelengths, dopant concentra-
tions, and energy transfer mechanisms are explained in detail. In the end, challenges and future scope in luminescence and
synthesis of SrY
2
O
4
are proposed. This review article gives a complete summary for the drawbacks and current challenging
issues of SrY
2
O
4
phosphors, which can give potential sprout for future work.
1 Introduction
In the present era, feld emission displays (FEDs) are in
high demand due to their high brightness, less power con-
sumption, low manufacturing cost, high contrast ratio,
high efciency, etc. [1–3]. To manufacture fat panel dis-
plays, phosphors play an important role. For this purpose,
rare earth-doped inorganic materials have attracted much
attention in the lighting industry. This is owing to the
unique luminescent properties arising from the f–f orbital
electronic transitions. In FEDs, the phosphors are oper-
ated at low excitation voltage (3–7 kV) and high current
densities (10–100 μA cm
−2
). Thus, the phosphors which
can be efciently operated at low voltages and resistant to
current saturation with stable chemical and thermal prop-
erties are required. Till now, many commercial sulfde-
based phosphors are used for commercial purposes such
as ZnCdS:Ag:Cl, ZnCdS:Cu:Al, ZnS:Cu:Al, Y
2
O
2
S:Eu,
Gd
2
O
2
S:Tb, and ZnS:Ag, Cl, SrGa
2
S
4
:Ce [4, 5]. However,
these phosphors are not eco-friendly. They degrade under
electron beam bombardment and release hazardous sulphur
gas. Under electron bombardment, electrons cause the for-
mation of oxides and sulphates which deposit on the screen
of the device, also known as “dead layer”. This decreases
the lifetime of the device and restricts the use of sulfde-
based phosphors in FEDs. Thus, potential phosphors are
required, which are thermally stable and eco-friendly. For
this purpose, oxide-based phosphors are considered as prom-
ising candidates due to their high physical, chemical, and
thermal stability, low phonon energy, and high bandgaps,
absence of blinking, gas free emission, and corrosion resist-
ant properties.
Among the various rare earth oxides, binary rare earth
oxides with structural composition ARE
2
O
4
(A = Ca, Sr,
Ba, Sr, RE = rare earth element) have become the topic of
luminescent researchers. These have been studied by vari-
ous researchers and are used in various lighting and display
devices due to their unique optical, magnetic, and thermal
properties [6–9]. Out of these inter oxides of alkaline earth
metals and rare earth elements; SrY
2
O
4
(SYO) has attracted
research interest. It is an inter oxide in Y
2
O
3
–SrO pseudo-
binary phase diagram. SYO possesses high physical, chemi-
cal, and thermal stability and also environment-friendly. Ear-
lier, SYO due to its high thermal and chemical stability was
* O. P. Pandey
oppandey@thapar.edu
1
Functional Materials Lab, School of Physics and Materials
Science, Thapar Institute of Engineering & Technology,
Patiala 147004, India
2
Department of Physics, R.T.M. Nagpur University,
Nagpur 440033, India