Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Investigation of Color Phosphors for Laser-Driven White Lighting

Al-Waisawy, Sara S.
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1417065501

Abstract Details

2014, Master of Science (MS), Ohio University, Electrical Engineering (Engineering and Technology).
Solid-state white lighting devices (SSWLDs) commonly use III-nitride near-UV or blue light emitting diodes (LEDs), combined with one or more phosphors, to generate white light. These devices already offer many advantages over traditional incandescent and fluorescent light sources, including long lifetimes, environmentally friendly designs without the need for mercury, and enormous energy savings. Despite unquestionable recent commercial success and the future potential for further development, current SSWLDs suffer from the droop effect limiting the overall efficacy and a thermally-induced shift in the peak emission wavelength of the phosphor. Thus, the overall efficiency of these devices can still be improved. One such example is to control the operating temperature of the device. When operating an LED, the temperature inevitably increases, yet the phosphor particles exhibit a loss in efficiency as the temperature of the device increases. In addition, LEDs suffer from efficiency loss and color instability with increased operating current, making high-power devices not achievable using LEDs as the excitation source. Recently, a new concept for developing SSWLD, based on laser diode (LD) substituting for LED as a pump source for exciting colour-stable phosphors, was proposed. In contrast to LEDs, laser diodes do not exhibit efficiency loss; many exhibit increased efficiency as current increases, and maintain color stability. Thus, there is a need in the art for improved solid-state white lighting devices that rely on laser diodes. In this project we have characterized individual Eu(WO4)2 (red phosphor), BaMg2Al16O27:Eu,Mn (green phosphor) and (Sr,Mn)2SiO4:Eu (blue phosphor) and trichromatic white light phosphors. Characteristics of light produced with each phosphor, variations with incident light power and phosphor temperature, as well as effects from phosphor ageing, are described. Results of comparison between pumping with coherent and incoherent light at the same wavelength are also described.
Wojciech Jadwisienczak (Advisor)
93 p.
Electrical Engineering
white light; phosphor; laser diode; integrating sphere

Recommended Citations

Citations

  • Al-Waisawy, S. S. (2014). Investigation of Color Phosphors for Laser-Driven White Lighting [Master's thesis, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1417065501

    APA Style (7th edition)

  • Al-Waisawy, Sara. Investigation of Color Phosphors for Laser-Driven White Lighting. 2014. Ohio University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1417065501.

    MLA Style (8th edition)

  • Al-Waisawy, Sara. "Investigation of Color Phosphors for Laser-Driven White Lighting." Master's thesis, Ohio University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1417065501

    Chicago Manual of Style (17th edition)

ohiou1417065501
899
© 2014, some rights reserved.Creative Commons License Investigation of Color Phosphors for Laser-Driven White Lighting by Sara S. Al-Waisawy is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Ohio University and OhioLINK.