LEDs Grown on Semi-Polar GaN Are 2.5 Times Brighter
The collaboration between Ostendo and TDI has resulted in LEDs much brighter than those grown on the conventional GaN c-plane.
Ostendo and TDI, part of the Oxford Instruments Group, have announced that LED structures grown on their semi-polar (11-22) GaN wafers have resulted in more than 2.5x the emission intensity of c-plane GaN based LED structures.
These results agree with research conducted by Sumitomo Electric Industries who discovered that green laser diodes (LD) grown on the semi-polar gallium nitride (GaN) plane are more efficient than those grown on the conventional c plane (see http://www.compoundsemiconductor.net/csc/features-details.php?cat=features&id=19732756 ).
Ostendo & TDI had entered into an Information Exchange Agreement with Palo Alto Research Center (PARC) in 2008. They agreed to make semi-polar GaN wafers available for PARC to grow LED and Laser Diode structures on and independently validate and report the achieved results.
As part of the validation, PARC has grown MQW LED structures on the semi-polar GaN side-by-side with a reference c-plane LED structure in the same MOCVD run. The LED structure grown on the semi-polar GaN achieved more than 2.5x more emission intensity than the reference LED structure grown on c-plane GaN. Also, the semi-polar GaN allowed for higher indium (In) incorporation resulting in longer peak wavelength of ~25 nm for the structure grown.
Further findings of this collaboration has recently been published as a feature article titled “Semi-polar nitride surfaces and heterostructures” in the October 2010 issue of the Physica Status Solidi Magazine.
“This is an excellent validation of our work in the semi-polar GaN area for the last two and a half years as it verified the main advantage of our semi-polar GaN and should help encourage LED makers to start considering it for future LED brightness improvements,” commented Hussein S. El Ghoroury, CEO of Ostendo.
“We are delighted that the production grade, semi-polar GaN wafers produced at TDI, which are as a result of research funded by Ostendo, has generated such encouraging results", added Frazer Anderson, Business Development Director at Oxford Instruments, "As a business, Oxford Instruments aims to use innovation to turn smart science into world class products, and this joint initiative with Ostendo and PARC meets our customers' needs through the advanced technology our companies have available.”
Earlier this year Ostendo and TDI announced the availability of semi-polar (11-22) GaN layer on sapphire substrate wafers using Ostendo’s proprietary design and TDI’s proprietary Hydride Vapor Phase Epitaxy (HVPE) technology. This joint development now provides the opportunity to leading High Brightness Light Emitting Diode (HBLED) and Laser Diode developers to increase optical efficiency significantly compared with structures grown on c-plane GaN substrates.
Ostendo Technologies is a developer of Solid State Light (SSL) based display technologies and products for commercial and consumer markets with the objective to achieve efficiencies and cost effectiveness at the material, the device and the system levels. Ostendo’s enabling technologies support products that are disruptive in their individual marketplaces.
TDI, a wholly owned subsidiary of Oxford Instruments, is a leader in the development of Hydride Vapor Phase Epitaxy (HVPE) processes and techniques for the production of novel compound semiconductors such as GaN, AlN, AlGaN, InN, InGaN. Using TDI HVPE technology, Oxford Instruments can produce templates for applications such as High Brightness Light Emitting Diodes (HBLEDs), Laser Diodes and High Electron Mobility Transistors (HEMTs).
PARC, a Xerox company, works closely with global enterprises, entrepreneurs, government agencies and partners, and other clients to invent, co-develop, and bring to market game-changing innovations by combining imagination, investigation, and return on investment for its clients.