| dc.description.abstract | Electricity is the main source of energy used for lighting but still worldwide, a
population of about 1.4 billion does not have any access to electricity, with 85 % of
them coming from rural areas. Most of the people in the rural areas use kerosene oil
as the main source of energy for lighting which produces smoke that does not only
pollute the environment but has adverse health effects on the people. CaAl2O4: Eu2+
,
Dy3+phosphor is a very promising source of energy in the future. It is
environmentally safe and involves less cost of installation and energy production.
Phosphors are solid substances that give off light, a phenomenon known as
luminescence and consist of a host matrix and dopants. In this work, effects of
synthesis temperature, defect, and pH on both structural and optical properties of
CaAl2O4: Eu2+, Dy3+ phosphor were investigated. Europium doped and dysprosium
co-doped Calcium aluminate nanomaterial (CaAl2O4: Eu2+, Dy3+) was prepared using
a facile solution combustion technique. Combustion synthesis method is better
compared than other conventional methods because of its benefits such as its low
synthesis temperature of 500 - 600 °C and its quick processing time. Furthermore,
the combustion method is an energy-saving technique that is highly exothermic, and
homogenous products are formed within a short time. Similarly, combustion
synthesis produces a much smaller grain size compared to alternative conventional
approaches. Although the phosphorescence of CaAl2O4:Eu2 is known, information
about the effect of different dopants and other synthesis conditions is scant. All the
synthesized samples underwent characterization employing a range of analytical
methods. The findings of X-ray diffraction (XRD) verified that every sample had the
monoclinic phase and all the peaks can be matched well with the typical monoclinic
CaAl2O4 peak matching with the ICDD data file (no.069-0033) for orthorhombic
structure. The anticipated chemical combustion results of the finished product were
provided by the Fourier-transform infrared analysis. The XRD patterns displayed that
there was a notable shift to higher 2theta of the prominent peaks diffraction angles
with change in synthesis parameters. This is attributed to an increase in particle sizes
which led to an increase in lattice parameters. The Debye-Scherrer relation was
utilized to ascertain the crystallite sizes of the samples in their prepared state. It was
noted that there is variation in the crystallite sizes with synthesis conditions. Analysis
of the UV-Vis spectra revealed that the absorption edges also shifted with synthesis
parameters. Images captured by a scanning electron microscope revealed that every
sample had pores and cracks in an uneven shape. The EDS outcome indicated that
the elements of the phosphor for all samples are components of O, Al, and Ca
indicating that the phase of final product was actually made of calcium aluminate.
The study offers a straightforward path to synthesize CaAl2O4: Eu2+, Dy3+ phosphors
with ideal pH, barium concentration, and synthesis temperature generating the
sample that exhibits the highest degree of crystallinity suitable for incorporation into
lighting fixtures. | en_US |
