What you’ll learn:
- What are OLEDs and how did they evolve?
- Types of OLEDs.
- What the future holds for OLEDs.
Great minds aspire to discover ideas that will change the world. We can all envision the “light bulb” moment when the connections between knowledge, creativity, inspiration, and innovation rapidly form and result in a novel concept. For Sherwin Seligsohn, the founding father of Universal Display Corporation, a literal light—a small green dot—set his mind in motion and inspired a path to a display revolution that has changed the way many of us see the world.
This pioneering journey began in the 1990s, when Seligsohn read about the novel research work on organic self-emissive organic materials by Drs. Forrest and Thompson. He decided to explore this groundbreaking technology with a visit to the electrical engineering school at Princeton University.
While there, he observed a green dot, with a 9-V battery hanging from it, light up for only a couple of seconds. From this tiny organic green dot, Seligsohn envisioned the future of display technology—energy-efficient OLEDs (organic light-emitting diodes).
Today, energy-efficient phosphorescent OLEDs emit light and color in about half of all smartphones worldwide and are used in devices including smartwatches, laptops and tablets, TVs, as well as AR/VR devices and automobiles. From the green dot discovery to modern OLED displays, numerous technological advances and a transformation within the display industry were required before OLEDs could be seen in popular electronics globally.
While a “light bulb” moment could happen instantly, the pace of innovation is often complex and steady, requiring a methodical effort of research and development to achieve breakthroughs, meet customer requirements, and unveil new paths forward.
OLEDs: From Idea to First Prototype
Before OLEDs entered the market, cathode-ray tube TVs were the dominant technology available to consumers. Though LCD TVs were still improving and gaining traction, the display industry was rife with opportunities to be disrupted.
However, the barriers to entry were high. Although backplane technology was maturing, the world didn’t have an OLED ecosystem that could support the proliferation of OLED displays throughout the consumer electronics landscape.
There were also complex scientific and engineering challenges, such as developing a commercial phosphorescent OLED (PHOLED) material with the necessary color and lifetime for high-performance consumer products. Consumers own and use devices for years, a far cry from the several seconds offered by the original green dot.
In addition to inventing and commercializing PHOLED materials that met consumer specifications, the innovative material had to be mass-produced in high volumes and with purity levels higher than some pharmaceutical drugs.
Meeting Customer Demands and Eliminating Barriers
Even after overcoming the initial scientific and engineering challenges, UDC also faced new challenges due to having PHOLED materials incorporated into devices. When display manufacturers were first introduced to OLEDs prior to the emergence of UDC’s technology, they weren’t immediately impressed because most associated the technology with inefficient fluorescent technology.
Furthermore, this kind of technology wasn’t competitive with LCDs because of the high-power consumption of fluorescent materials. When UDC introduced PHOLEDs with the possibility of reducing power consumption by a factor of three to four, OLEDs became compelling.
Existing OLED display panel manufacturers began to warm to the idea of using phosphorescent OLED technology due to its ease of adoption. However, engineers needed to update the design of the TFT backplane used to drive the display. Because backplane changes are routine in a design-in cycle, panel makers could introduce energy-efficient OLED technology into production quickly and realize the benefits of phosphorescence.
Another convincing feature was the groundbreaking form factors and stunning visual performance that OLEDs make possible. While LCDs are typically limited by the rigidity of glass, OLEDs are thin film layers that can be deposited on glass, plastic, or even metal foil. OLEDs are inherently conformable, bendable, and rollable. While this trait could not be immediately utilized in the early days of OLED, it was part of the ubiquitous OLED future envisioned by Seligsohn and UDC.
Finally, OLEDs have excellent visual performance due to the wide color spectrum, fast response times, near-infinite contrast ratio under dark conditions, thin form factor mentioned above, and 180-degree viewing angle. With PHOLEDs adding energy efficiency to the list of attributes, manufacturers were keen to take advantage of OLEDs’ benefits in a range of consumer applications.
OLED Technology: Ready for Prime Time
In the early days of the OLED market, the primary consumer electronics applications were cell phones and MP3 players. With battery life being a critical factor in mobile products (as it continues to be today), improvements in OLED technology and materials enabled OEMs to deliver more efficient displays than the mainstream display technology of LCDs.
The first commercial display utilizing phosphorescent OLED technology was released in 2003 with a Fujitsu flip phone. The phone used red PHOLED material as part of a small sub-display on the front of the closed clamshell phone, which allowed the viewer to see the time and date. Only three years later, phosphorescent OLED material was designed into the first commercial active-matrix OLED display of a cellphone, the BenQ-Siemens S88.
The actual rise of OLEDs came when smartphones were introduced into the market. With the advent of the smartphone, quality displays and performance prompted consumers to shift from using their phones primarily for telephone and text to using them as multipurpose devices.
In 2010, Samsung Electronics ignited the industry by unveiling its flagship Galaxy S model smartphone, which featured an OLED display. Samsung’s commitment to high-quality, energy-efficient OLED displays bolstered the OLED industry, prompted huge capacity investments, and sparked the proliferation of OLEDs.
What’s Next for the OLED?
Since the advent of energy-efficient phosphorescent OLEDs, Seligsohn’s company has continued to make breakthroughs in high-performing, highly efficient display materials and technology that enable low-power, eco-friendly displays and lighting. OLEDs are quite literally everywhere we look, from our modern-day smartphones to TVs, smartwatches, laptops, AR/VR headsets, screens in cars, and more.
While a tiny green dot started a cascade of research and innovation that pioneered a path forward and supported the OLED industry, those of us who understand this technology’s power still feel there’s much more ahead.
The growing importance of energy efficiency is driving the best scientists and engineers working in OLED technology to push boundaries. The commercial phosphorescent OLED portfolio currently includes red and green (mostly used for mobile phones, tablets, and laptops), as well as yellowish green (for certain OLED TV recipes).
OLED devices using PHOLEDs are significantly more energy-efficient than LCDs, and Universal Display is the sole source supplier of these materials to the world’s largest display panel makers. The forthcoming addition of the company’s phosphorescent blue into the market in 2024 is expected to further increase OLED display energy efficiency by approximately 25% as well as enhance performance capabilities in products across consumer electronic markets.
Plasmonic PHOLEDs and Flexible Substrates
UDC’s team is also working on the research and development of Plasmonic PHOLEDs, which centers on a proprietary and novel device architecture that extends the OLED panel’s lifetime and enhances its efficiency. This work is part of the company’s long-term energy-efficiency roadmap to broaden OLED solutions. Continual improvements in energy efficiency results in higher performance, longer battery life, and brighter displays in a variety of devices, from small smartwatches to big-screen TVs.
Another significant development comes from the fact that OLEDs are more widely deposited on flexible substrates. This means that displays are no longer made on flat, breakable glass but rather highly flexible, bendable, and rollable plastic and other substrates. This opens a vast array of new opportunities for displays that can be seamlessly integrated into everyday devices and be folded, rolled, and curved without compromising visual quality or performance.
In fact, some market analysts estimate that the foldable smartphone market will quadruple to 55 million units by 2025, with companies like Google, Oppo, Samsung, Vivo, and Xiaomi already offering foldables.
Finally, the automotive industry is becoming an increasingly important market for OLEDs as more automakers envision the dashboard of the future and release new electric-vehicle models. OLEDs’ interior displays in our cars, taillights, and even mirrors can be enhanced to allow for wider viewing angles, better performance in extreme temperatures, improved energy efficiency, and more.
From the invention of phosphorescent OLED technology to the discovery, development, and delivery of next-generation OLED materials and technologies, the legacy of the green dot and Seligsohn’s work are supporting UDC and the OLED industry as we collectively continue envisioning, shaping, and strengthening the future of OLED technology.