Measurement of Luminescence Intensity Fluctuation Parameters of Local Regions of the Light Emitting Diode Crystal in the Electric Breakdown Mode

This paper describes an experimental set for recording optical emission in local regions of a light-emitting diode crystal in the microplasma breakdown mode and a technique for estimating the parameters of fluctuations of the optical emission intensity. The technique is based on pixel-by-pixel processing of images obtained by a video camera. The results of measurements and estimation of parameters of fluctuations of intensity of the microplasma emission at breakdown of Cree XREGRN-L1-0000-00P01 LEDs of green luminescence colour are presented. It is shown that the spectrum of these fluctuations in the frequency range 0.04 - 10 Hz obeys the law of the form 1/f
^γ
, where the exponent of degree γ decreases from 0.90 to 0.76 as the reverse current of the LED increases from 2 to 10 μA. The dynamic characteristics of the intensity of the microplasma optical radiation can be used for diagnostic purposes in nondestructive testing of LEDs.