Luminous efficacy of radiation(K) and color-rendering index(Ra) are two important parameters of LEDs.Generally,high luminous efficacy of radiation is obtained at the sacrifice of color-rendering index.The requirement of correlated color temperature(CCT) differs for various application environments.Considering the fixed CCT of 3 000 ± 10 K,we adjusted spectrum parameters of the tri-color white LEDs,such as peak wavelength,full width at half maximum(FWHM) and relative optical power ratio,to obtain...