Degradation Mechanisms in Optical Materials for Solid State Lighting Applications
In this investigation,the degradation mechanisms of Bisphonel A Polycarbonate (BPA-PC) plates under blue light radiation at 140℃are studied.Two series of pure 3 mm thick BPA-PC plates were used in this study.One series exposed to the blue radiation at 140℃ up to 90 days,and second series were kept at 140 ℃ without irradiation of blue light.Optical properties of the photo-aged plates were studied using Integrated sphere and Lambda 950 spectrophotometer.The results in both series show that increasing the ageing time leads to the discolouration,loss of optical properties,decrease of light transmission,and increase in the yellowing index (YI) of BPA-PC plates.In both photo-and thermally-aged samples experiments confirm that there are two stages in the variation of yellowing indexes.In photo-aged samples,the YI is overall higher than that in thermally-aged samples,inferring that blue light radiation has a great influence on the discolouration of BPA-PC plates.
Polycarbonate Thermal-degradation Photo-degradation Yellowing LED Encapsulant Reliability of optical materials
M.Yazdan Mehr W.D.van Driel K.M.B.Jansen P.Deeben M.Boutelje G.Q.Zhang
Material Innovation Institute(M2i), Delft, The Netherlands ;DELFT University of technology, EEMCS Fa DELFT University of technology, EEMCS Faculty, Delft, The Netherlands ;Philips Lighting, Eindhoven, DELFT University of technology, Industrial design Faculty, Delft, The Netherlands Philips Lighting, Eindhoven, The Netherlands
国际会议
9th China International Forum on Solid State Lighting(第九届中国国际半导体照明论坛)
广州
英文
208-210
2012-11-05（万方平台首次上网日期，不代表论文的发表时间）