Wide-band-gap semiconductor light-emitting diodes (LEDs) have been among the most successful of photonic technologies. As with everything else, researchers continue to seek ways to make these devices ever smaller, to drive new nano-applications. But electrically pumped nanoscale LEDs have an Achilles’ heel: efficiency droop, the tendency of the LEDs’ quantum efficiency to fall off when the current density pumping them exceeds a certain threshold.
Now, a multi-institution U.S. research team
reports a tiny LED that seems to get around these limitations. The new device, based on a p-n hetrojunction featuring slender fins of zinc oxide, reportedly continues to gain brightness as more current is pumped in.
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