18. What determines the service life of LEDs? It is believed that the LEDs are extremely durable. But it's not quite true. The larger current is passed through the led during his service, the higher the temperature and the faster the aging occurs. Therefore, the lifetime of power LEDs is shorter than that of low-power signal, and now stands at 20 – 50 thousand hours. Aging is expressed primarily in the reduction of brightness.
When the brightness reduced by 30% or half of the led must be changed. 19. 'Port' is the color of the led over time? The aging of the led is connected not only with a decrease in its brightness, but with a change in color. There are currently no standards which would allow to quantify the change of color LEDs in the aging process and compare with other sources. 20. Not bad for a led for the human eye? The emission spectrum of the led close to monochromatic, what it's fundamental difference from the spectrum of the sun or incandescent lamps. Is this good or bad – is not known for sure, because as far as I know, serious research in this area never carried out.
There are no data on the harmful effects of LEDs on the human eye is missing. 21. Which of today, there are manufacturing technology of LEDs and led modules? With regard to crystal growth, then basic technology – Organometallic Epitaxy. For this process requires especially pure gases. In the modern facilities provided for automation and control of gases, their separate threads, fine-tuning gas temperature and substrates.