We are surrounded by displays. They provide us with information at all times – everything from the latest news and the breaking movie to our fitness level and the quickest route from A to B.
LED technology laid the foundation for high-quality color-intensive video walls and LCD screens. It was followed by OLED technology offering high color contrast, wider viewing angles and flexible designs. Today, the increasing volume of data creates the need to display as much information as possible in the smallest possible space, in real time and in the highest quality. MicroLED technology is expected to meet the demands of the display industry, promising exceptionally brilliant colors at very low power consumption, very high brightness and resolution, great reliability, fast response times and flexibility.
ams OSRAM is in a unique position as it offers application and product expertise in LEDs, sensors, and drivers. Julia Halasz heads the Displays business line and is therefore well versed in this topic.
Julia, can you briefly explain what a microLED display is?
MicroLED displays are based on tiny LED devices that are used to directly generate the individual pixels. Each of these pixels consists of individual red, green and blue LEDs as independently controllable sub-pixels.
MicroLEDs today have an edge length of about 50µm. We don’t think that this size will have a disruptive market effect, so we are focusing on chip edge lengths of 10µm and less. Just to give you an idea, there is enough space on a 1-euro coin for more than four million microLEDs, that’s four million separate functioning LEDs.
In addition to their brilliant colors and all the benefits already mentioned, microLED based displays have the potential to integrate sensors and infrared LEDs to enable touch, brightness and motion sensing. Some of those features are alre ady available and mounted behind OLED displays, and this is particularly interesting for future developments in smartphones and wearables.
The extremely small dimensions make manufacturing very challenging. Why do we need this complex technology when we have other established display technologies?
To gain market shares from those well-established technologies, which are also evolving significantly, microLEDs must deliver on all its promises.
It promises to combine some of the really important features that industry is looking for, such as high image quality, brilliant colors and good readability even in bright sunlight. For this you need a technology that offers a wide color gamut, high contrast, wide viewing angles, high pixel density and fast refresh rates. That is exactly what microLEDs can provide, and better even than incumbent technologies.
Energy efficiency is of course also very important. As microLED displays only draw power for lit pixels, their system efficiency is high. Depending on the application, this results in significantly lower power consumption, longer battery life and cost savings.
In specific applications, such as in the automotive sector, displays also face demanding conditions including extreme temperatures and humidity, so solutions are needed that are very robust and durable. Here, microLED displays rely on the underlying LED technology which offers long lifetimes and reliable operation in a wide range of temperatures.
You and your team are closely involved in these activities. Which possible application impresses you most?
That’s not easy to answer. Once you’ve seen a microLED display, you will be totally impressed by the incredible difference in image quality. The viewing experience, for example on a TV, is enhanced by pure and vivid colors and an almost unlimited field of view. MicroLEDs also enable modular, seamless designs and pave the way for large borderless TV diameters. The biggest challenges here are the large screen diameters, the high number of pixels and suitably mature production processes to ensure cost competitiveness over incumbent technologies. But we are rapidly catching up here.
What impresses me more than the possible applications is the development work that is being carried out throughout the world. You need to remember that we cannot build on existing manufacturing processes or equipment. The whole supply chain must take a new path. MicroLED manufacturing needs a holistic approach; it is almost impossible for one company alone to combine all the technologies under one roof. LED, equipment and display manufacturers must work closely together.
We can bring five decades of experience in optical semiconductors. What drives us is the need to anticipate the future and turn those visions into today’s products.