EFFECTS OF TEMPERATURE, DEFECT, AND ph ON PROPERTIES OF caal2o4: Eu2+, Dy3+ PHOSPHOR FOR LIGHTING APPLICATION

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.