LG Display, the display making arm of LG Electronics, says it has created a new and lower-cost OLED panel that will help to accelerate the technology’s growth in the TV and monitor markets.
The key innovation is that the new display uses only two OLED emissive layers instead of three, which enables the company to reduce its manufacturing costs without sacrificing much in terms of image quality, compared to its existing three-stack OLED panels.
The company unveiled the two-stack white OLED panel this week at K-Display Business Forum in South Korea. UBI Research, which first reported on the development, said that the new display was able to produce a comparable level of picture quality to the company's existing Primary RGB Tandem OLED displays at temperatures of under 6.500 kelvin and 10,000 kelvin. It also supports a wider colour gamut than the existing three-stack OLED panel, while lowering its operating voltage by four volts.
LG Display said at the event it hopes that the two-stack architecture could one day replace the three-stack design it uses now. Previously, it was necessary to stack an additional layer of organic emissive material onto its panels to achieve higher brightness and colour accuracy and improve the overall lifespan, but the company has now found a way to get comparable performance using just two stacks. That’s good news, because using an additional layer means higher production costs and energy consumption.
The limitations of two-stack architectures have been overcome through a combination of new materials and device engineering, LG Display said at the event. More specifically, it is utilising a new blue emissive material, which allows it to replace its conventional yellow-green emissive layer with separate red and green layers. According to LG Display, this enhances the blue light output of OLED while increasing the white-screen colour temperature to around 6,700 kelvin. It has also optimised the placement of these new emissive layers to try and reduce colour shift and enhance wide angle viewing.
By reducing the number of emissive layers from three to two, LG Display can get away with using less of the expensive materials that go into OLED displays. It also makes the deposition process easier, while the reduction in voltage means that power delivery and thermal management are simplified, reducing the display’s overall energy consumption and manufacturing costs.
This is a big deal because price is one of the few areas where LCD displays continue to hold a significant advantage over OLED. Most believe that OLED outperforms LCD in terms of contrast ratio, black level performance, colour reproduction and response times. However, OLED panels still cost much more than LCD panels, which means the technology is still only really found in higher-end TVs and monitors. If LG Display wants to expand the OLED market, it’s going to need to find a way to reduce its manufacturing costs.
Most existing OLED TVs and monitors today utilise LG Display’s three-stack architecture, but last year the company introduced a new four-stack Primary RGB Tandem OLED display that separates the red and green emissive layers for its flagship products. UBI Research said LG Display is likely to persist with the four-stack Primary RGB Tandem OLED panels for higher-end products going forward, because they still deliver slightly better picture performance, but the two-stack architecture will enable it to target products at more accessible prices.
“LG Display will be able to defend its position in the premium segment while expanding into the mid-range TV and monitor markets, where LCD and Mini-LED technologies remain dominant,” said UBI Research Fellow Kim Jung-Keun.
