ИСТИНА

The work is dedicated to a comprehensive description of the process of degradation of LEDs; identify different patterns of dependency and aging of the LED as a single device, as well as its individual components: crystal and phosphor. The results are compared with data and theoretical models of other authors. The study was carried out changes in the parameters of LEDs at different ambient temperatures (from 70 ° C to -10 ° C). The result of the experiment was that it was shown that the luminous flux of LEDs is considerably reduced with time. This is due to degradation of a crystal operating at elevated temperature and current, and the phosphor burn. It has been found that the degradation processes proceed unevenly to the crystal and the phosphor. It was designed and experimentally confirmed the degradation factor for the white phosphor LEDs type studied. It has been identified and explained by the growth of the LED voltage during its functioning. Varshni ratio was experimentally confirmed. It was confirmed by a very negative impact both on the high temperature efficiency, and on the duration of LEDs operation within acceptable parameters.