Current and optical noise of GaN∕AlGaN light emitting diodes

Low frequency noise of current and light intensity of ultraviolet light emitting diodes (LED) with wavelength from 265to340nm are the superposition of the 1∕f and generation-recombination noise. The dependence of generation-recombination noise on the LED current has a maximum caused by a relatively shallow trap level in the quantum well. The upper bound of this trap level concentration is estimated to be Nt=7×1015cm−3. The relative spectral noise density of the light intensity fluctuations decreased with an increase of the LED forward current. At high currents, the difference in the noise level for LEDs with different wavelength is small and is of the same order of magnitude or even smaller than for visible LEDs.