Perovskite-based light emitting diodes (LEDs) could be the key to developing internet bandwidths orders of magnitude faster than what is now available, while also keeping energy consumption and cost down, researchers have claimed. Other potential applications lie in laser technology.
Perovskite is a natural mineral first identified in Russia’s Ural Mountains in 1839 and composed primarily of calcium, titanium, and oxygen – all in the 10 most common elements in the Earth’s crust. The mineral gave its name to a class of materials based on the same elements but doped with small quantities of others. For almost the first two centuries after their discovery, these perovskites were largely a curiosity of interest only to chemists.
More recently, however, the ability of perovskites to display different electrical properties depending on the atoms with which they are doped has turned them into a wonder material. Perovskites now represent one of the most efficient ways to trap energy from sunlight and are continuing to improve at unprecedented rates. Moreover, perovskites have the potential to be manufactured far more cheaply than traditional silicon-based solar cells, while a layer of perovskite over a silicon base could capture more light than either on their own.
A decade ago, when the potential of perovskites to capture light was being revealed to the world, it was also noted that they could offer better ways to release it, providing more efficient and flexible LEDs. To a planet in the middle of a combined climate and energy crisis, that seemed like something of an afterthought, although of course if our LED TV screens need less power to light them that’s an obvious win.
However, researchers at the Universities of Cambridge and Surrey have demonstrated perovskite LEDs’ capacities could be more than an afterthought. They’ve announced control over metal-halide perovskite LEDs that produced modulation bandwidths of 42.6 MHz and data transmission rates of more than 50 Mbps. The authors think this is just the beginning, with bandwidths in the gigahertz range possible. At maximum speeds, this consumes a lot of energy per bit, but throttling back to speeds sufficient for most purposes makes the systems far less energy-hungry.
For decades, physicists have seen photonics as the future of data processing, replacing electrons with photons that literally move at the speed of light. Making it happen in practice has proven more difficult than hoped, however.
Speeds are limited by the capacity of the transmitting devices, far more than by the movements of the information-carrying photons. However, the team thinks the capacity of perovskite LEDs to switch on and off with lightning speed could be the advance that is needed. Perovskites can also be built into substrates, including silicon chips, integrating them directly into the processing devices.
“We provided the first study to elucidate the mechanisms behind achieving high-speed perovskite LEDs, which represents a significant step toward the realization of perovskite light sources for next-generation data communications,” said University of Cambridge PhD student Hao Wang in a statement.
“The ability to achieve solution-processed perovskite emitters on silicon substrates also paves the way for their integration with micro-electronics platforms, presenting new opportunities for seamless integration and advancement in the field of data communications.”
The study is published in Nature Photonics.