Imec, a globally renowned research and innovation hub specializing in nanoelectronics and digital technologies, has unveiled a groundbreaking perovskite LED stack which emits light that is a thousand times brighter than state-of-the-art OLEDs. This significant achievement, detailed in the current issue of Nature Photonics, represents a crucial step towards the development of a perovskite injection laser with promising applications in image projection, environmental sensing, medical diagnostics, and beyond.
Light-emitting diodes (LEDs) have transformed contemporary lighting and sensing technology, finding diverse applications in residential, industrial, and electronic settings, including indoor lighting, TV screens, and biomedical devices. Despite the widespread use of organic LEDs (OLEDs), such as those in smartphone screens, their maximum brightness remains constrained, particularly in bright outdoor conditions.
In contrast, perovskite materials, known for their specific crystal structure, have demonstrated potential beyond solar cells. Possessing exceptional optoelectrical properties, cost-effective processability, and efficient charge transport, these materials have emerged as compelling candidates for light emission applications, including LEDs.
While perovskites exhibit resilience to very high current densities, achieving laser operation with the emission of high-intensity coherent light has remained elusive. Imec's ULTRA-LUX project has achieved a significant advancement by introducing a PeLED architecture with low optical losses and driving these PeLEDs to current densities capable of supporting stimulated emission of light. This innovative architecture includes transport layers, transparent electrodes, and perovskite as the semiconductor active material, enabling operation at electrical current densities tens of thousands of times higher (3 kA cm-2) than conventional OLEDs.
Imec's breakthrough involved enhancing amplified spontaneous emission using electrical assistance in conjunction with conventional optical pumping. As a result, the institute demonstrated that electrical injection contributes 13 percent to the total amount of stimulated emission, approaching the threshold for achieving a thin-film injection laser. This milestone paves the way for high-power thin-film laser diodes and opens the door to innovative applications of thin-film perovskite lasers.
The findings have been published in the article titled 'Electrically Assisted Amplified Spontaneous Emission in Perovskite Light Emitting Diodes' in Nature Photonics. The ULTRA-LUX project, supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No.835133) with an Advanced Grant to Prof. Paul Heremans, is scheduled to continue until September 30th, 2024.
Image credits: Imec
