Research on Degradation of GaN-Based Blue LED Caused by γ Radiation under Low Bias

Abstract EN

GaN multiquantum-well blue light-emitting diodes (LEDs) were radiated with 60Co γ-rays for accumulated doses up to 2.5 Mrad (SiO2).

The radiation-induced current and 1/f noise degradations were studied when the devices operate at the low bias voltage.

The current increased by 2.31 times, and the 1/f noise increased by 275.69 times after a dose of 2.5 Mrad (SiO2).

Based on Hurkx’s trap-assisted tunneling model, the degradation of current was explained.

γ radiation created defects in the space-charge region of LEDs.

These defects as generation-recombination centers lead to the increase in the current.

In addition, based on the quantum l/f noise theory, the degradation of 1/f noise might be also attributed to these defects, which caused an increase in the Hooge constant and a decrease in the carrier lifetimes.

The current and 1/f noise degradations can be attributed to the same physical origin.

Compared to the current, the 1/f noise parameter is more sensitive, so it may be used to evaluate the radiation resistance capability of GaN blue LEDs.