05 Oct 2007
The New York company is looking to use high-quality polar and non-polar AlN substrates to boost UV LED performance.
Crystal IS has received a US contract for $2 million to improve the performance of deep-ultraviolet LEDs, and ulimately make them competitive with conventional mercury UV lamps.
“The money will be spent on a development program to use AlN substrates to develop high efficiency, high power UV LEDs with long lifetime,” said Tim Bettles, Crystal IS' vice president of business development, sales and marketing.
The three-year program will run from November and aims to produce 280 nm LEDs with a performance that is “significantly higher” than current industry-best performance.
“Current state-of-the-art UV LEDs operate at 2 percent wall-plug efficiency and have a lifetime of less than 1000 hours,” Bettles said. “While this is OK for some R&D and analytical applications, the bigger markets such as germicidal disinfection require considerably better performance.”
This award comes from the US National Institute of Standards and Technology's Advanced Technology Program, under which Crystal IS had performed a previous contract that finished in September.
In that contract Crystal IS had developed the world’s first 2-inch AlN substrates cut from boules at its Green Island, New York, laboratories. Now, the company will use its expertise gained in growing AlN in its quest for high-power UV-LEDs.
“Bulk low defect AlN substrates offer advantages for many applications where high aluminum compositions are required, including UV LEDs. Low defect levels will increase the internal quantum efficiencies and lengthen the lifetime of short wavelength LEDs,” Bettles said.
“In addition, because we grow this material in the bulk we can cut not only c-plane substrates, but also non-polar and semi-polar substrates, both a- and m-plane. This helps reduce the internal electric field within the device and improves IQE.”
• Crystal IS has also separately appointed Stephan Mueller as vice-president of engineering. Mueller's experience is in crystal growth and he will head up the company’s engineering effort in this area.
“Stephan is internationally recognized for his achievements in the field of wide bandgap semiconductors and has tremendous knowledge of crystal growth at volume production levels that will be key as Crystal IS continues on its path to commercialization,” said Ding Day, CEO of Crystal IS.