Study of electrophoretic phosphor applied on light-emitting diodes

• Main Authors: Jau-An Bai, 白詔安
• Other Authors: 陳文瑞
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/46g6m3

碩士 === 國立虎尾科技大學 === 光電與材料科技研究所 === 97 === Literatures about reliability and dispense of LED know, in order to accelerate the development of solid-state lighting, we must overcome the problem made by tradition dispense phosphor gel converted blue light emitting diodes. In this study, the phosphor particle are uniform dispersed in solvent and then electrophoresis deposition forms uniform deposition on cathode electrode under an apply voltage. After the suspension done, the experiment through changing the parameter condition, such as apply voltage, phosphor concentration, deposition time, DI water percentage and different substrate. We discuss the relationship among the weight and thickness of electrophoretic phosphor and the apply voltage, concentration, deposition time. Besides, we also discuss how the percentage change of DI water could influence electrolyte and whether deposition in different substrate would form the structures’ variation. In the electrophoretic phosphor basic study, the apply voltage at 200V under the concentration of phosphor varies and then we can controls deposition thickness approximately 16 to 40 micrometer. The white light of phosphor by blue LED emitting correlated color temperature (CCT) to achieve approximately 3800 to 6000 K rages. The white light uniform values define CCT variation. Therefore, the CCT variation value to achieve approximately 80 to 1500 K. The high CCT observed variation value bigger of phosphor thickness and packing density relation. For this reason, the EPD phosphor methods to achieve uniform white light and increase external extraction efficiency than tradition white LED. In addition, we knows CCT variation value to come from blue LED chip light emitter amount and phosphor packing density influence. In the future, the EPD phosphor study can focus improvement phosphor packing density.