Failure modes in GZO FC-light-emitting diodes

GaN-based light-emitting diodes (LEDs) with Ga-doped ZnO (GZO) as current spreading layer was fabricated and investigated. At 350mA injection current, the light output power of GZO LED degraded 6% after 554 h under stress of 85°c/85%RH. We could see the current crowding effect appeared in GZO LEDs. The junction temperature of GZO LEDs became higher could exacerbate the devices. It was also can be find that the mainly reason of decay in GZO LEDs was the Ag layer of GZO LEDs generated AgO in the aging process. Lots of AgO in Ag layers resulted in a decline of reflectance could reducing the optical power of the device, and it might weaken the reliability of the LED device.