Progress of Reliability and Failure Mechanisms for GaN‐Based Light‐Emitting Diodes

Abstract

To achieve high reliable GaN-based LEDs with a controllable lifetime is one of the key issues for applications. In this review, an overview of reliability studies for different GaN-based LEDs, especially the research progress in our group based on our specially designed in situ multifunctional highly accelerated aging test system over the past few years, is presented. The contents not only cover highpower GaN-based LEDs, mid-power GaN-based LEDs, deep UV GaN-based LEDs, micro-LEDs, and phosphors under different operating conditions but also include the influence of point defects on the degradation, the correlation between luminous flux and color quality, and so on. Finally, prospects for reliability are discussed with the further development of the GaN-based devices.

A Critical Review of Lighting Design and Asset Management Strategies. Illuminating Practices and Lessons Learned for Swedish Public Libraries

“…According to the literature, the failure of a LED lighting system can broadly be categorized as catastrophic type or parametric type. These failure modes are attributable to thermal, electrical, mechanical, environmental, chemical, and radiation stress factors [31]. There are two typical criteria for measuring LED lighting reliability or life expectancy, lumen maintenance and light source consistency through 3 common test methods [32].…”

“…ANSI/IES LM-80[36] is the most recent version of the original standard used by the industry to measure and project the life of LED packages. The associated measuring method follows ANSI/IES TM-21-21[31]. In addition to LED packages, arrays, and modules, the LED system should comply with ANSI/IES LM-84-20+E1[38] which builds on the LM-80 document for measuring luminous flux maintenance of LED systems.…”