SPD Change of HP LED Under Increased Temperature Stress

High power light emitting diodes (HP LED) are energy efficient light sources that have been developing at great speed. Aging process was performed at increased pin temperatures, with approximate values of 80°C, 90°C and 100°C and constant current. The conditions in chambers are simultaneously monitored for approximately 5000 hours. The change in HP LED's SPD was small and for the second test group was within the narrower wavelength interval than for the first. This interval corresponds to the phosphor emission region and indicates that important factor of white LED's SPD stability is the choice of type of phosphor used.