TiO_2微粒对远程荧光粉膜及白光发光二极管器件光色性能的影响
|
摘要
利用热压法将TiO_2微粒掺入至YAG:Ce荧光粉和硅树脂中制备出远程荧光粉膜并封装成白光发光二极管(LED)器件,通过荧光粉相对亮度仪、双积分球测试系统和可见光光谱分析系统对样品的光色性能及机理进行了研究.结果表明:TiO_2的散射效应能够显著提高蓝光的利用率和黄光的透射强度,白光LED器件的光通量在TiO_2浓度为0.966 g/cm~3时达到最高值415.28 lm(@300 mA,9.3 V),提高了8.15%,相关色温从冷白6900 K逐渐变化至暖白3832 K.TiO_2的掺入不仅提高了远程荧光粉膜的发射强度和白光LED器件的光通量,同时能调控其相关色温.
Based on the hot pressing method,the remote phosphor films are prepared by adding TiO_2 particles into YAG:Ce and silicon binder,and then they are packaged into white light emitting diode(WLED) device with chip on board(COB)blue light source.The photo-chromic properties and mechanism are studied and calculated.Based on Mie theory and Henyey-Greenstein function,forward scattering is the main light scattering form of YAG:Ce phosphor powder,while the forward scattering intensity is close to the back scattering intensity of TiO_2 particles.The emission spectral intensity and relative luminance of remote phosphor film change with increasing the concentration of TiO_2 particles,and the optimum concentration is 0.966 g/cm3.Forward transmission intensity and back reflection intensity are calculated and analyzed,when the concentration of TiO_2 is low,the forward transmission intensity of blue light is stronger than that of yellow light and the main transmission form is forward transmission,while the forward and backward intensity of yellow light are similar because of isotropy.With increasing the concentration of TiO_2,the forward intensity of blue light gradually decreases,and the transmission intensity is lower than that of yellow light.The forward and backward intensity of yellow light reach their maxima when the TiO_2 concentration is 0.966 g/cm~3.The main reason for this phenomenon is that the increasing of the utilization ratio between blue light and transmission of yellow light is affected by the strong scattering ability of TiO_2.Finally the WLEDs are packaged by remote phosphor films and COB blue light source,the luminous flux of WLED reaches 415.28 lm(at 300 mA and 9.3 V) at a concentration of 0.966 g/cm~3,which is increased by 8.15%compared with the concentration in the case of no TiO_2 mixing.Besides,the correlated color temperature changes from cool white 6900 K to warm white 3832 K gradually.Consequently,the adding of TiO_2 particles can not only improve the emission intensity of remote phosphor film and the luminous flux of WLED,but also regulate the correlated color temperature.
Based on the hot pressing method,the remote phosphor films are prepared by adding TiO_2 particles into YAG:Ce and silicon binder,and then they are packaged into white light emitting diode(WLED) device with chip on board(COB)blue light source.The photo-chromic properties and mechanism are studied and calculated.Based on Mie theory and Henyey-Greenstein function,forward scattering is the main light scattering form of YAG:Ce phosphor powder,while the forward scattering intensity is close to the back scattering intensity of TiO_2 particles.The emission spectral intensity and relative luminance of remote phosphor film change with increasing the concentration of TiO_2 particles,and the optimum concentration is 0.966 g/cm3.Forward transmission intensity and back reflection intensity are calculated and analyzed,when the concentration of TiO_2 is low,the forward transmission intensity of blue light is stronger than that of yellow light and the main transmission form is forward transmission,while the forward and backward intensity of yellow light are similar because of isotropy.With increasing the concentration of TiO_2,the forward intensity of blue light gradually decreases,and the transmission intensity is lower than that of yellow light.The forward and backward intensity of yellow light reach their maxima when the TiO_2 concentration is 0.966 g/cm~3.The main reason for this phenomenon is that the increasing of the utilization ratio between blue light and transmission of yellow light is affected by the strong scattering ability of TiO_2.Finally the WLEDs are packaged by remote phosphor films and COB blue light source,the luminous flux of WLED reaches 415.28 lm(at 300 mA and 9.3 V) at a concentration of 0.966 g/cm~3,which is increased by 8.15%compared with the concentration in the case of no TiO_2 mixing.Besides,the correlated color temperature changes from cool white 6900 K to warm white 3832 K gradually.Consequently,the adding of TiO_2 particles can not only improve the emission intensity of remote phosphor film and the luminous flux of WLED,but also regulate the correlated color temperature.
引文
[1]Zukauskas A,Shur M S,Caska R 2002 Introduction to Solid-State Lighting(New York:John Wiley)pp1-6
[2]Liu S,Luo X B 2011 LED Packaging for Lighting Applications(New York:John Wiley)pp1-28
[3]Hu R,Luo X B,Zheng H 2012 J.Appl.Phys.21 09MK05
[4]Xiao H,LüY J,Xu Y X,Zhu L H,Chen G L,Gao YL,Fan X G,Xue R C 2014 Chin.J.Lumin.35 66(in Chinese)[肖华,吕毅军,徐云鑫,朱丽虹,陈国龙,高玉琳,范贤光,薛睿超2014发光学报35 66]
[5]Dong M Z,Wei J,Ye H Y,Yuan C M,Zhang G Q 2013J.Semicond.34 053007
[6]Tsai P Y,Huang H K,Sung J M,Kan M C,Wang Y H2015 IEEE Electr.Dev.Lett.36 250
[7]Narendran N,Gu F,Freyssinier-Nova J P,Zhu Y 2005Phys.Status Solid A 202 R60
[8]Allen S C,Steckl A J 2007 J.Disp.Technol.3 155
[9]Lin M T,Ying S P,Lin M Y,Tai K Y,Tai S C,Liu CH,Chen J C,Sun C C 2010 Photon.Technol.Lett.22574
[10]Lin M T,Ying S P,Lin M Y,Tai K Y,Tai S C,Liu CH,Chen J C,Sun C C 2014 IEEE Trans.Dev.Mat.Re.14 358
[11]Xiao H,Lu Y J,Shin T M,Zhu L H,Lin S Q,Pagni PJ,Chen Z 2014 IEEE Photon.J.6 1
[12]Tian H,Liu J W,Qiu K,Song J,Wang D J 2012 Chin.Phys.B 21 098504
[13]Chen H C,Chen K J,Lin C C,Wang C H,Han H V,Tsai H H,Kuo H T,Chien S H,Shih M H,Kuo H C2012 Nanotechnology 231
[14]Song Y H,Ji E K,Bak S H,Kim Y N,Lee D B,Jung M K,Jeong B W,Yoon D H 2016 Chem.Eng.J.287511
[15]Henyey L G,Greenstein J L 1941 Astrophys.J.93 70
[16]Qian K Y,Ma J,Fu W,Luo Y 2012 Acta Phys.Sin.61204201(in Chinese)[钱可元,马俊,付伟,罗毅2012物理学报61 204201]
[17]Liu Z Y 2010 Ph.D.Dissertation(Wuhan:Huazhong University of Science and Technology)(in Chinese)[刘宗源2010博士学位论文(武汉:华中科技大学)]
[18]Liu Z Y,Liu S,Wang K,Luo X B 2010 Appl.Opt.49247
[19]Hsiao S L,Hu N C,Wu C C 2013 Appl.Phys.Express6 032102
[20]Heller W 1965 J.Phys.Chem.69 1123
[2]Liu S,Luo X B 2011 LED Packaging for Lighting Applications(New York:John Wiley)pp1-28
[3]Hu R,Luo X B,Zheng H 2012 J.Appl.Phys.21 09MK05
[4]Xiao H,LüY J,Xu Y X,Zhu L H,Chen G L,Gao YL,Fan X G,Xue R C 2014 Chin.J.Lumin.35 66(in Chinese)[肖华,吕毅军,徐云鑫,朱丽虹,陈国龙,高玉琳,范贤光,薛睿超2014发光学报35 66]
[5]Dong M Z,Wei J,Ye H Y,Yuan C M,Zhang G Q 2013J.Semicond.34 053007
[6]Tsai P Y,Huang H K,Sung J M,Kan M C,Wang Y H2015 IEEE Electr.Dev.Lett.36 250
[7]Narendran N,Gu F,Freyssinier-Nova J P,Zhu Y 2005Phys.Status Solid A 202 R60
[8]Allen S C,Steckl A J 2007 J.Disp.Technol.3 155
[9]Lin M T,Ying S P,Lin M Y,Tai K Y,Tai S C,Liu CH,Chen J C,Sun C C 2010 Photon.Technol.Lett.22574
[10]Lin M T,Ying S P,Lin M Y,Tai K Y,Tai S C,Liu CH,Chen J C,Sun C C 2014 IEEE Trans.Dev.Mat.Re.14 358
[11]Xiao H,Lu Y J,Shin T M,Zhu L H,Lin S Q,Pagni PJ,Chen Z 2014 IEEE Photon.J.6 1
[12]Tian H,Liu J W,Qiu K,Song J,Wang D J 2012 Chin.Phys.B 21 098504
[13]Chen H C,Chen K J,Lin C C,Wang C H,Han H V,Tsai H H,Kuo H T,Chien S H,Shih M H,Kuo H C2012 Nanotechnology 231
[14]Song Y H,Ji E K,Bak S H,Kim Y N,Lee D B,Jung M K,Jeong B W,Yoon D H 2016 Chem.Eng.J.287511
[15]Henyey L G,Greenstein J L 1941 Astrophys.J.93 70
[16]Qian K Y,Ma J,Fu W,Luo Y 2012 Acta Phys.Sin.61204201(in Chinese)[钱可元,马俊,付伟,罗毅2012物理学报61 204201]
[17]Liu Z Y 2010 Ph.D.Dissertation(Wuhan:Huazhong University of Science and Technology)(in Chinese)[刘宗源2010博士学位论文(武汉:华中科技大学)]
[18]Liu Z Y,Liu S,Wang K,Luo X B 2010 Appl.Opt.49247
[19]Hsiao S L,Hu N C,Wu C C 2013 Appl.Phys.Express6 032102
[20]Heller W 1965 J.Phys.Chem.69 1123