E-Mail IMAGE: Researchers at Linköping University, Sweden, have developed efficient blue light-emitting diodes based on halide perovskites. view more Credit: Thor Balkhed Researchers at Linköping University, Sweden, have developed efficient blue light-emitting diodes based on halide perovskites. "We are very excited about this breakthrough", says Feng Gao, professor at Linköping University. The new LEDs may open the way to cheap and energy-efficient illumination. Illumination is responsible for approximately 20% of global electricity consumption, a figure that could be reduced to 5% if all light sources consisted of light-emitting diodes (LEDs). The blue-white LEDs currently in use, however, need complicated manufacturing methods and are expensive, which makes it more difficult to achieve a global transition.