Efficiency droop

The term "efficiency droop" refers to the decrease in luminous efficacy of LEDs as the electric current increases above tens of milliamps (mA). Instead of increasing current levels, light output is usually increased by connecting multiple LED emitters in parallel and/or series in one lamp. Solving the problem of efficiency droop would mean that household LED lamps would require fewer LEDs, which would significantly reduce costs.

Early suspicions were that the LED droop was caused by elevated temperatures. Scientists showed that temperature was not the root cause of efficiency droop. The mechanism causing efficiency droop was identified in 2007 as Auger recombination, which was taken with mixed reaction.A 2013 study conclusively identified Auger recombination as the cause.

Some lasers have been adapted as an alternative to LEDs to provide highly focused illumination

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