Hi there, how one can compute the spectral power distribution of white LED ,i,e like black body radiator that has a formula of calculation..
There are three main methods of mixing colors to produce white light from an LED:
Because of metamerism, it is possible to have quite different spectra that appear white. However, the appearance of objects illuminated by that light may vary as the spectrum varies
- blue LED + green LED + red LED (color mixing; can be used as backlighting for displays)
- near-UV or UV LED + RGB phosphor (an LED producing light with a wavelength shorter than blue's is used to excite an RGB phosphor)
- blue LED + yellow phosphor (two complementary colors combine to form white light; more efficient than first two methods and more commonly used)
Spectral power distribution refers to the distribution of light energy across the visible spectrum. It is important for white LED because it determines the color quality of the light emitted, as well as its efficiency and energy consumption.
The spectral power distribution of white LED is calculated by measuring the intensity of light emitted at various wavelengths using a spectrometer, and then plotting the data on a graph. This graph shows the relative intensity of light at each wavelength and can be used to determine the SPD of the LED.
The spectral power distribution of white LED can be affected by several factors, including the materials used in the LED, the design of the LED chip, and the phosphor coating used to convert blue light into white light. Environmental factors such as temperature and humidity can also affect the SPD of white LED.
The spectral power distribution of white LED directly affects its color rendering ability, which is the ability to accurately reproduce colors. A balanced SPD that covers a wide range of wavelengths results in better color rendering, while a skewed or narrow SPD can lead to poor color rendering and color distortion.
Yes, the SPD of white LED can be adjusted through various methods such as using different phosphor coatings, altering the LED chip design, or using filters to modify the light output. These adjustments can improve the color quality, efficiency, and overall performance of white LED.