AlN substrates will dictate future of UV LEDs
The ability of solid-state technology to displace mercury discharge lamps from the $500 million ultra-violet illumination market will hinge on the availability and quality of AlN substrates.
However volume substrate production will begin to address this need before the end of this year, according to Yole Développement s 2009 UV LED market report.
This will lead to a rapid expansion in global production of LEDs emitting UV-C wavelengths, opening up a total $250 million overall market for UV LEDs by 2015.
“Using AlN substrates will help to grow high-quality AlGaN layers with a high aluminum content for deep UV-C emission,” explained author Philippe Roussel.
Today, the efficiency of the shortest wavelength UV-LEDs is limited by defects formed during the growth of active layers on non-native substrates like sapphire.
Consequently 90 percent of 2008 s UV LED sales were for lower aluminum content emitters in the UV-A and UV-B areas of the spectrum, between 280 nm and 400 nm.
While this wavelength range successfully addresses a number of markets, including money counting and adhesive curing, it does not satisfy the needs of the UV sterilization. The report suggests that the first large scale sales for the crucial air and water disinfection end market will begin in 2010.
It predicts that UV-C LEDs emitting between 200 nm and 280 nm will penetrate this application to a level where they constitute half of all LED sales by 2013. By 2015, UV-C LEDs will account for over two-thirds of overall $250 million UV LED market.
Roussel points out that UV-C LEDs are currently at least 50 times more expensive than UV-A LEDs. “This gap has to be filled,” he told compoundsemiconductor.net. “By 2011 we should see some UVC products exhibiting reasonable pricing.”
In 2008, Japan s Nichia, Korea s Seoul Optodevice and US manufacturer Sensor Electronic Technology together accounted for three-quarters of all UV LED sales.
These players are increasingly being joined by producers of AlN substrates expanding their business, observes the report.
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