Researchers at MIT have discovered that LEDs can emit more light power than electrical power consumed, with some LEDs reaching an efficiency of 230%. This groundbreaking finding challenges traditional LED efficiency standards. By lowering the applied voltage, the input power decreases while the emitted light power remains constant, resulting in increased efficiency. The excess heat generated from the LED cooling process is used to create more light. Although not practical for cooling purposes, this technique could pave the way for highly efficient LEDs and potentially be utilized for solid-state cooling or power generation applications.
https://phys.org/news/2012-03-efficiency.html