Light-emitting diodes (LEDs) may be the most energy efficient light-generating technology we have now, but scientists have found a way to make them even more efficient. Using perovskite, a mineral found abundantly in the Earth’s mantle, as the semiconductor, the LED can produce light more efficiently at a cheaper cost the conventional LEDs. While producing this technology with perovskite is a relatively new thing, scientists say they already perform as good as the best LEDs on the market—suggesting there’s plenty of room for improvement.