Study On The Spectral Optimization Of White LED

White LED has many advantages,recognized as one of the most promising high-tech fields at the 21 st century.At present,CRI(color rendering index)and CQS(color quality scale)are widely used in the international evaluation of color rendering,but these two kinds of color rendering indicators have certain defects.Through the comprehensive analysis of the shortcomings of CRI and CQS,after a lot of experimental calculation,it is reported a new color rendering index CRI* was improved and put forward.Based on the LLE model,the spectral optimization of different kinds of white LED was studied.In this paper,the spectral model of PC-W LED,PC/R-W LED and QD-W LED are established respectively,and the objective function with LLE as the optimization objective is established.We have studied the LLE of these three kinds of white LED under different color rendering property evaluation index(CRI,CQS,CRI*)and different color rendering requirements of Q(Q = not required,50,70,80,90,95,98)at different color temperatures(2700K-6500K),and made a comparison.The results show that the LLE of the PC/R-W LED is higher under the same conditions,because there is no red phosphor in the PC/R-W LED and the half width of the red light is narrow,so the energy loss is small.For the theoretical spectral model of PC-W LED,the value of LLE under the CRI * is generally higher than the value of LLE under CRI and CQS when Q = 70,80,90,95 at CCTs of 2700 K to 6500 K.This is because the CRI and the CQS are calculated by chromatic aberration,when the chromatic aberration is large,the color rendering property is low,and LLE is high,but CRI* in the calculation of color rendering property has considered the hue difference and the color saturation difference,compared with CRI and CQS,under the same chromatic aberration CRI* has improved the color rendering property.For the real spectral model of the PC-W LED,the value of LLE under the CRI* constraint is generally higher than the value of LLE under CRI and CQS constraints when Q = 80,90,98 at CCTs of 2700 K to6500K.For the theoretical and real spectral models PC/R-W LED,the LLE value under the CRI*constraint is generally higher than the value of LLE under CRI and CQS constraints when Q = 50,70,80,90 at CCTs of 2700 K to 6500 K.For the QD-W LED theoretical spectral model,the LLE value under the CRI* constraint is generally higher than that under the CRI and CQS constraints when Q = 70,80,90 at CCTs of 2700 K to 6500 K.For the real spectral optimization of CCT tunable QD-W LED,at CCTs of 2700 K to 6500 K,when Q = 90,the value of LLE under the CRI*constraint is similar to that under the CRI constraint,which is higher than that under the CQS constraint;when Q = 95,the LLE value under the CRI* constraint is lower than that under the CRI constraint and higher than the value of LLE under the CQS constraint;When Q = 98,the value of LLE under the CRI* constraint is lower than that of CRI and CQS.In this paper,the spectral model of correlated color temperature(CCT)tunable R/Y/C-W LEDs with CRI> 98 and R9> 98 also has been optimized.Under conditions of both CRI andspecial CRI of R9 for strong red above 98 at CCTs of 2700 K to 6500 K,the value of CQS can reach more than 95,and the LLE can reach 267-282lm/W.The peak wavelength of the red LED is633.0nm and the FWHM is 20.0nm.In the PC-Y LED the peak wavelength of the blue LED chip is 452.6nm,the FWHM is 25.7nm,the peak wavelength of the green phosphor is 512.0nm,the peak wavelength of the orange phosphor is 580.0nm,In the PC-C LED the peak wavelength of the blue LED chip is 452.6nm,the FWHM is 25.7nm,the peak wavelength of the green phosphor is512.0nm.In the actual package,the Al Ga In P red LED(?R=635nm,??R=23nm),the In Ga N blue chip(lb=454nm,??b=30nm)in the PC-Y LED and PC-C LED,G2060(lg=512nm)and O5446(lor=586nm)phosphor are chose.The real CCT tunble R/Y/C-W LED can realize the white light with CRIs of 97-99,R9 s of 98-99,R(9-12)s of 90-95,CQSs of 95-97,and LEs of 122-132 lm/W at CCTs of 2731 K to 6533 K.