In colloquial English, “Seeing Red” is a bad thing. But when it comes to display quality in electronics, it can mean quite the opposite. As we cross the 10th year of the PFS phosphor’s entry into the display market, it’s interesting to look back and see how far the industry has come. In contrast to typical broad-band phosphors such as red nitride that were on the market decades ago, PFS is a narrow-band red phosphor that enables wide color gamut without sacrificing brightness in display technology. This results in more true-to-life color, and a more immersive viewing experience.
As much as it has transformed the display industry, PFS was not originally invented for it. GE Lighting originally funded its research and development for bright, warm LED lighting with high efficiency. While that effect was achieved, market introduction of PFS into general lighting has been gradual. Through a detailed analysis of the display industry and the shortcomings of liquid crystal displays (LCDs), the GE Licensing team determined that PFS would be the fastest path to greatly improve the color output of the display since phosphor changes would not require any other changes in LCD design.
At the time, there was a weakness in the display market in the sharpness of colors emitted by the display. Display manufacturers were often faced with a choice between display brightness and color sharpness. That’s because, while the prior red phosphors could improve color sharpness, their emission band extend into the invisible infrared region.
Collaborating with their colleagues at GE Lighting, GE researchers Anant Setlur and Jim Murphy discovered that the red phosphor potassium fluorosilicate paired with manganese (PFS) could eliminate the compromise between brightness and appearance. They were able to connect the dots between the output of this PFS and the technical and market needs in the display industry.
At the time, the R&D focus was different than it is today, as it was more centered around investing in programs for use exclusively in GE products for commercial and residential lighting. However, seeing the potential in the PFS program, the GE Licensing team, believed that the best path to market would be by looking for licensing partners in the display industry. That was easier said than done.
It took a year of work on developing the PFS program and demonstrating that, by licensing it in a non-competing market, it could generate additional revenue.
The first licensing partner was Sharp, and the teams from both GE and Sharp worked together on perfecting PFS and making it work well in a LED package. Once Sharp introduce its initial products, the market began to take notice and requests for additional PFS LEDs began to increase. This demand led to additional PFS licensees and the program to become a successful part of the overall GE Licensing portfolio.
Through the execution of over 20 licenses, GE Licensing activated and created this market. Before the introduction of PFS into display applications, it was not a commercial material, just a laboratory curiosity. A different red phosphor, red nitride was commonly employed, but that phosphor did not generate the excellent red that PFS generated. Early on, they faced an important choice: license to one or two players and let them dominate the market, or license non-exclusively. They chose to do that latter and create fair competition. Today, more than 50 billion LEDs containing PFS have been sold into display technology, with an estimated 80% of the global LED manufacturers licensed under the GE patents and technology.
The original patents focus on the use of PFS in a LED, and that means anyone who puts PFS in an LED would be require a license from GE prior to selling a PFS containing LED. GE Licensing has since expanded the list of patents included in the license offer and continues to file patents on new inventions.
When GE Licensing began licensing PFS, there was not enough PFS being manufactured to meet demand. GE Licensing invested $2 million into the business unit to setup manufacturing. In 2021, they were divested and became GE Licensing’s manufacturing partner, Current Chemicals.
GE Licensing continues to invest in R&D and grow the program. Having signed over 20 licenses globally, they understand where the market is headed. The team is currently working to develop and bring to market newer versions of phosphors for the next wave of development. Innovating for next generation displays that do or will incorporate Mini LED and Micro LED technology has required researchers to solve interesting technological challenges. For example, the team has done innovative work on making smaller particle size PFS, as well as the coatings and surfactants necessary to move from an on-chip LED package to film and ink configurations.
The success of the PFS program was no accident. The initiatives GE Licensing took to invest in this technology and set up an entirely new market took years. In many ways, the program is a great example of how GE Licensing approaches the monetization of intellectual property. They look at research and technology differently. GE Licensing’s methodology allows for the use of GE technology to solve important problems and introduce these technologies to new industries.