Osram in pilot production with GaN-on-silicon high-power LEDs

High-brightness LED prices have been dropping sharply even as their lumens/Watt has been increasing. Here’s a technology development that should serve to  drive prices even lower, albeit we won’t see the results for at least two years: Osram has announced that it’s in the pilot stage of producing high-performance blue LEDs grown in gallium-nitride layers on 6-in. silicon wafers. (Blue LEDs combined with a dollop of phosphor form the basis for white solid-state lights.) Currently blue LEDs’ production process requires a sapphire (aka expensive) wafer. Osram’s GaN-on-silicon LEDs are already being tested under practical conditions, meaning so we can see these LEDs reach the market in as little as two years.

The company says, “Quality and performance data on the fabricated LED silicon chips match those of sapphire-based chips: …1 mm² chips driven at 350 mA.  In combination with a conventional phosphor converter in a standard housing — in other words as white LEDs — these prototypes correspond to 140 lm at 350 mA with an efficiency of 127 lm/W at 4500K.”

This development follows the move in power MOSFETs, where GaN-on-silicon devices are beginning to appear from companies such as International Rectifier, EPC, and Transphorm. In the MOSFET world, the ability of GaN devices to routinely switch in the MHz+ range is the draw.