Institut Penyelidikan dan Teknologi Nano Optoelektronik (INOR) - Tesis

Browse

Browsing Institut Penyelidikan dan Teknologi Nano Optoelektronik (INOR) - Tesis by Subject "Institut Penyelidikan dan Teknologi Nano Optoelektronik"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Design Optimization And Characterization Of White Light For Led Street Light Application
    (2022-06)
    Ying, Jocelynn Kee Xiao
    The aim of this study was to evaluate the effects of lens type and shape on the light performance from surface mounted device light emitted diode (SMD LED) street light. Another factor considered was the influence of various shapes of the light emitting surface (LES) on the SMD LEDs and size of the SMD LED on light distribution. Besides, the effects of varying correlated colour temperature (CCT) of the LEDs were also investigated. Optical characterization was carried out using the Goniophotometer (GO-2000) and Integrating Sphere (PCE-200A). DIALux Evo software was used to perform the simulation. Road parameters, such as pole distance of 35 m and pole heights of 8 m on a 7 m width road were used. The road requirement was according to the Tenaga Nasional Berhad (TNB), whereby the street lights must comply with ME4A road classification requirements. The findings showed that Lens E demonstrated a better light performance as compared to Lens A, Lens B, Lens C and Lens D, owing to the rectangular shape of Lens E. The smaller shape of the rectangular lens with classification of Type II-M has lesser light pollution problems. A study comparison between the different CCTs was conducted. Warm White was selected for further investigation into the different shape and size of SMD LEDs as well as key colour for colour mixing.
  • Thumbnail Image
    Publication
    Synthesis And Characterization Of Organic-inorganic Bismuth Halide Perovskites For Photonics Applications
    (2023-09)
    Heng, Han Yann
    The study focused on synthesizing organic-inorganic Bi-halides perovskite compounds using different halides (iodide, bromide, and chloride) in a low-toxic and eco-friendly manner. The aim was to develop Pb-free perovskite materials that are less hazardous for workers in the photonics industry and that can be produced using inexpensive and less complicated processes. In this regards, a hydrophobic phenylammonium cation ([(C6H5)NH3]+) was selected, which is known to contributed to a better sample stability. The synthesis methods involved three different approaches: one step solvent (OSS), OSS added oleic acid (OA), and a non-coordinated solvent method at different temperatures. The stability of the samples were evaluated, and it was observed that the ones synthesized at 60 °C exhibited the best stability for most of the solvents and types of halides. The strong ionic interaction between the BiX63- anion and the short short PhA+ cations in the 0D structure greatly contributed to its stability. In general, the PhA4BiCl6 sample showed the highest stability among the halides due to the stronger attraction between nucleus and electron. The study also involved the growth of a single crystal of PhA4BiI6 using a solvent evaporation technique from which the structure of the zero-dimensional (0D) perovskite compounds was determined, supported by field emission scanning electron microscopy with energy-dispersive X-ray (FESEM-EDX) and Fourier transform infrared (FTIR) spectroscopy results