Review—Reliability and Degradation Mechanisms of Deep UV AlGaN LEDs

There are numerous applications for deep UV AlGaN Light-Emitting Diodes (LEDs) in virus inactivation, air and water purification, sterilization, bioagent detection polymer curing. The long-term stability of these LEDs is also interest long-duration space missions such as the Laser Interferometer Space Antenna (LISA), first gravitational wave detector space. We review literature on aging devices a function drive current, temperature dc versus pulsed operation. typically show gradual decline output power (up to 50%) over extended operating times (>100 h) rate mainly driven by current temperature. Experimentally, degradation dependent cube density exponentially main mechanism this appears be creation/migration point defects. Pre-screening considering ratio band edge-to-midgap emission LED ideality factor effective identifying populations that long lifetimes (>10,000 h), defined falling 70% initial value.