Effect of Blending Different Types of ZnS Phosphors on the White Electroluminescence

• Main Authors: Po-Way Chen, 陳柏偉
• Other Authors: In-gann Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/55630993788084265431

碩士 === 國立成功大學 === 材料科學及工程學系碩博士班 === 92 === 　　This research is to investigate the effect of mixing methods and parameters on luminescent properties of blending the blue-green and orange of ZnS phosphors. This study is also to examine the optical performance of ZnxCd1-xS：Cu, Cl synthesized by solid state with various x values as well as with different copper concentration. The X-ray diffraction was utilized to characterize the crystal structure of prepared ZnCdS. The optical properties were measured, including Photo- luminescence ( PL ) spectroscopy, Electro- luminescence ( EL ) spectroscopy, and Chromaticity coordinates(CIE). 　　Blending of the blue-green and orange phosphors in the weight ratio of 1：5 . The high intensity of electroluminescence is achieved by suspending mixed phosphors in castor oil. It is found that the result in chromaticity coordinate (CIE) values of (0.322, 0.345) under 300V 1000Hz, which is located in white color region. However, the CIE values mentioned above was shifted a little to the green color. Furthermore, an equation and a correction parameter was generated from the laws of color addition and experimental results to evaluate the CIE values of mixing phosphors regarding to the weight ratios and the brightness difference of the blue-green and orange phosphors. 　　In order to improve shift the CIE value to white light, the red electroluminescent phosphor was synthesized by alloying of ZnS and CdS. The results show that emission peak was located at 630nm and 665nm in red region, as x is equal to 0.4 and 0.3, respectively. And the best electroluminescence intensity was obtained by alloying 60 mole% of CdS in ZnS and doping 2600ppm copper.