III-Nitride UV emitters and their applications

III-Nitride UV light emitting diodes (LEDs) have an enormous applications potential for air & water purification, food disinfection, polymer curing and bio-medical instrumentation. However the growth and processing of these devices is very challenging due to the high Al-fraction AlGaN layers needed for deep UV emission. Since early 2000, our research group has developed III-N deep UV LEDs (emission wavelength < 300 nm) over sapphire substrates. The key to our success was the use of a new pulsed epitaxy procedure and new device designs to mitigate junction heating issues. In this paper we will review the progress to date which has led to large area deep UV LED lamps with cw-powers approaching 100 mW.