1/f noise characterization gamma irradiation of GaN-based blue light-emitting diode

Abstract

The electrical model that ionizing radiation reduces the effective power output of GaN-based blue light-emitting diode is proposed by investigating the light/dark current generation mechanism in active region of GaN-based blue light emitting diode device under ionizing irradiation. The model that the ionizing radiation increases the 1/f noise of GaN-based blue light-emitting diode device is proposed by studying the 1/f noise mechanism of the active region of GaN-based blue light-emitting diode device under exposure to ionizing radiation. In the small injection region (I1 A)， the space charge region and the recombination current increase with irradiation dose increasing. Meanwhile, with the increase of the ionizing-irradiation-generated defects, the 1/f noise amplitude increases. In the large injection region (I1 mA), due to the dominant influence of the series resistance, the surface recombination velocity and current increases with irradiation dose increasing. Meanwhile, with the increase of ionizing-irradiation- generated defects, the 1/f noise amplitude increases. The I-V and 1/f noise test results before and after irradiation are in good agreement with theoretical results. In the middle injection region (1 A I 510-5 A), due to the competition between mobility fluctuation caused by energetic carrier scattering and the carrier number fluctuation caused by the newly irradiation-generated defects, as the radiation dose increases, 1/f noise has no significant changes in the frequency domain. However, through the 1/f noise time domain multiscale entropy complexity analysis, a conclusion can be drawn that with the increase of radiation dose, the 1/f noise domain multi-scale entropy becomes more complex. 1/f noise amplitude ultimately proves to be sensitive to reflect the reliability of GaN-based blue light-emitting diode ionizing irradiation in the case of small injection and large injection. The greater the noise amplitude, the higher the irradiation induction trap is, and the greater the generation-recombination current related to the dark current, the smaller the photocurrent related to the diffusion current is, so that the luminous efficiency of the device, the optical output power, and other performance parameters decrease, thus affecting the reliability of the device and resulting in the more failure devices. 1/f noise time domain multiscale entropy complexity can reflecte ionizing irradiation reliability of GaN-based blue light emitting diodes sensitively in the middle injection region.The more the multiscale entropy complexity, the bigger the irradiation induction generation-recombination current is, and the worse the reliability of the device is. The present study provides a method of characterizing the GaN-based blue light-emitting diode ionizing irradiation reliability according to 1/f noise.