Since the rebrand of Facebook to Meta, there has been a lot of buzz around the metaverse and how it will impact our society. The extension of ourselves that we present in virtual spaces is quickly changing our sense of reality and will continue to do so if we start spending more time in immersive worlds, such as the metaverse, to do activities such as working, shopping and gaming. The metaverse will likely take technological immersion to a new level by using improved VR/AR headsets, which will require low power consumption coupled with high brightness and contrast, and there is a race between the major players in tech to develop suitable VR/AR equipment. Meta has recently revealed a new (and enormous) AI supercomputer for supporting the metaverse, but could innovation at the pixel-level of LED consumer displays help enable a more immersive user experience?
There are such clear and significant advantages to LED technology that it’s no wonder LEDs have rapidly transformed lighting, illumination, and display technologies. Whether by drastically decreasing the environmental impact of lightbulbs, or by enabling high-quality organic LED (OLED) TVs, LEDs have transformed our visual environment and become a household name in the process. However, until the recent LED takeover, most people probably knew of LEDs as dim red bulbs for classroom electronics circuits, or for a TV remote. So, how did those simple bulbs transform into the cutting-edge technologies we have today? And could they transform even further into something enabling virtual and augmented reality?
What are LEDs?
Fundamentally, an LED is a diode – a simple electronic component that is usually based on semiconductor materials. Like the semiconductor transistors that underpin modern computing, the origins of LED technology date back more than 50 years, and an early LED was patented in 1966 (US patent 3293513).
However, silicon doesn’t emit light, so unlike the silicon chips of computing, LEDs are typically based on complicated compound semiconductors from the III and V groups of the periodic table (such as GaAsP - gallium arsenide phosphide). Different semiconductor materials emit different colour light, so different colour LEDs can be created by mixing elements into different compounds, with the periodic table providing a colour palette. However, to work well in LEDs, those semiconductor compounds must be manufactured with highly precise, nanoscale, crystalline quality. That’s a huge technological challenge and has produced vast amounts of research and innovation. Moreover, the periodic table palette does not provide obvious materials for blue LEDs.
The importance of LED intellectual property
Due to the vast amount of semiconductor research that was required, even the seemingly-simple matter of producing a blue LED, which in turn enabled a white LED, won the inventors the 2014 Nobel Prize in Physics. In addition, blue LEDs sparked a major patent entitlement dispute between one of those Nobel laureates, Shuji Nakamura, and their employer, Nichia Corporation (one of the world’s largest suppliers of LEDs), with the inventor receiving a pay out of over $8 million. LEDs are behind numerous other patent disputes, involving Nichia, Seoul Semiconductor, Osram, Samsung, and other players, so the rise in the use of LED technology due to the metaverse may cause a substantial increase in patent activity.
The growing desire for tiny tech
Recently, another similarity between transistors and LEDs has become notable: LEDs are getting smaller. Moore’s law is a well-known observation that the number of transistors on a microchip doubles about every two years. LEDs have an analogous version with Haitz’s law, which effectively means that today’s cutting-edge LEDs could be made smaller and more cheaply in future.
There are a few widespread LED technologies commonly used in TVs, such as quantum dot LEDs (QLEDs) and OLEDs. QLEDs build on liquid crystal displays (LCDs) and use quantum dots to emit light and enhance displays by reducing colour bleeding commonly found in LED technology. Conversely, OLEDs use a distinctly different technology in that the pixels emit their own light. In the push to reduce the size of LEDs for brighter and more robust screens with better contrast, new LED technologies such as mini LEDs and microLEDs are now being developed. Mini LEDs are similar to QLEDs, although with smaller backlights, and can be compared to a single pixel due to being about one fifth of the size of conventional LEDs. MicroLEDs are even smaller at only half the size of mini LEDs. Therefore, leading the way on reducing size are microLEDs, which allow more pixels into more space and could be the next big display technology (provided the current global chip shortage doesn’t stop them in their tracks).
MicroLED displays are expected to have similar properties to high-end OLED displays, with excellent clarity and energy efficiency, and could also be more robust and resistant to burn-in than OLEDs. However, in a microLED array, the size of each LED is so small that the display requires an entirely new manufacturing process. Pixels of a particular material (and hence a particular colour) are developed separately and then three sheets of respective red-blue-green pixels are combined to give a colour display. Tiny pixels must be overlaid with very high precision over a large area in order for the technology to meet its potential. However, if research and innovation can overcome the current challenges, as happened with blue LEDs and white LEDs, then microLEDs could create a very high-quality, lightweight, and energy efficient display technology that would be well-suited to VR or AR headsets.
The advantages of microLEDs have already been identified by various players in the semiconductor field including LG, who is one of the biggest names in microLED display technology for televisions. This can also be seen by the huge growth in patent applications for technology involving both microLEDs and AR/VR since 2015.
Materials for the metaverse
For the metaverse to seamlessly integrate with our reality and allow us to create a true extension of ourselves online for activities such as working, shopping, and gaming, VR and AR graphics must improve. For that, innovative LEDs could be essential.A lightweight, super-realistic display could be perfectly suited to the next generation of VR and AR glasses, enabling those technologies to offer improved graphics and realism for immersive experiences.
If you have any questions about semiconductors, the metaverse or LEDs, please contact Caitlin Tysoe, Tomos Thomas or your usual Kilburn & Strode advisor.