Red phosphor in Glass
MetadataShow full item record
Massive electricity demands every year consume a lot of energy. So, consumption of energy has been a topic that is discussed widely due to alarming environmental threats like global warming. Thus, energy-saving technology is highly demanded. The lighting consumes a big part of electricity, which motivates the large effort to develop a better efficiency in illumination technology. Phosphor in glass is a technique that has brought a significant improvement in the solid-state lighting industry in terms of giving the desired color, stability in chemical and thermal properties, is environment-friendly and has a longer lifespan. Thus, it has been commercially accepted in the lighting market and has a start to replace traditional fluorescent lighting. In this thesis project, phosphor powder was developed in our group, and glass powder was purchased in the market. The host matrix used is yttrium molybdate doped with a red activator, Eu3+: Y(MoO4)3, and silicate glass powder was used to embed phosphor powder. We aim to optimize the ratio of phosphor over the glass, sintering process for high-performance phosphor glass. The characterization will be followed to guide the analysis and optimization plan. A scanning Electron microscope (SEM) was used to check the morphological structure of fabricated samples. Excitation and emission spectrum were investigated with Fluorospectrometer. Quantum efficiency was measured using a home-built setup and transmittance was investigated with a UV-VIS spectrophotometer. The excitation spectrum of phosphor in glass samples had a dominating peak at 395 nm at an emission of 616 nm. The emission peak was dominating at 613 nm when it was excited at a wavelength of 465 nm. The CIE chromaticity coordinates were almost near to the National Television Standard Committee (NTSC) with high color purity. The CIE chromaticity coordinates of NTSC for red phosphor is (x=0.67, y=0.33) and our samples 5% and 10% had (x=0.64,y=0.35) and sample 15% displayed (x=0.65 and y=0.34) respectively. It was noticed that 15% phosphor in glass displayed a brighter violet color when the blue laser is irradiated on the red phosphor sample. Upon excitation at 465 nm, the quantum efficiency increased with a high phosphor/glass ratio while there was a decrease in transmittance as the phosphor/glass ratio increased.