Osram have been nudging the efficiency horizon upward again. Their blue Osram Oslon Square now has a typical forward voltage of only 2.87 V at 85°C, instead of the 3.05 V specified so far in the data sheet
– the lowest typical values in this component class worldwide. Depending on the operating point, this translates into an increase in efficiency of these light emitting diodes of 6% to 8%, which can be transferred to the entire UX:3 chip family. These chips can be found in all blue and white LEDs. The LEDs are used in an extremely wide range of applications – the Osram Oslon Square, for example, in street lighting and industrial lighting. “The reduction in forward voltage was achieved thanks to a new process in the epitaxy”, said Dr. Marcus Eichfelder, Project Manager at the Regensburg high-tech company. Production of the first optimised chips started this past August.
There is still enormous potential. “In the laboratory we have already succeeded in further reducing the forward voltage by as much as 30 mV”, said Dr. Joachim Hertkorn, Epitaxy expert at Osram Opto Semiconductors. This would improve the efficiency of the LED chips by a further percentage point. “In view of the speed with which this first step has been implemented, we are confident that the improved process can be transferred to production by the summer of 2015”, added Hertkorn. “Any further reductions in forward voltage will then only be marginal owing to the laws of physics.”
