| | | The 72% mystery
toastr: "What are reasons to stay long, and what would be a good exit point or time?"
This is the time of the quarter to ask ourselves these questions.
I completely agree with slacker's points about the danger of SummerSprout and the disappointment of blue being not the game changer it had been advertised to be, but merely a modification to a niche product.
Is there an optimistic side? Is there anything potentially positive that we should consider beyond the simple hope that there will be a breakthrough tomorrow?
Home about this, the latest (Aug 2025) OLED investor presentation
How do explain page 10, which makes this claim:
Current performance (2025) Red & green PHOLED w/fluorescent blue. Decreased 72% Energy consumption compared to 2015.
What would you have guessed as the efficiency improvement since 2015? A few percent? But 72%?
Green started full commercial production Q1 2013. Up through 2012 the best free online location for the latest info on UDC's materials was the annual DOE Solid State Lighting Workshop. I just checked and those old presentations have finally been taken down. Anyway, by 2012 UDC had essentially achieved 100% internal quantum efficiency. Where could they go from there? What could have changed since 2015?
Maybe a tenth of a volt or two were shaved from the emitting layer or blocking layer? Maybe, but not enough to explain 72%.
It seems to me the lion's share for the 72% reduction must be extraction efficiency, also called light out-coupling efficiency. Page 8 of the presentation claims that Light Out-Coupling is a significant part UDC's IP.
A simple bottom emitting OLED, even if it has 100% internal quantum efficiency, only emits 20-25% (external quantum efficiency) of the light generated in the emissive layer. The rest is reflected back and absorbed. So there's a lot of potential there.
Note Plasmonic PHOLED, which impacts both light outcoupling and triplet lifetime, is shown as a separate IP. All the papers I've seen on plasmonics involve two-sided TOLEDs, and use a random array of tiny silver cubes to alter the surface plasmons. There is no reason to believe this has affected the 2015-2025 efficiency timeline.
We really don't know much at all about what UDC themselves has accomplished in light out-coupling. But Dr. Stephen Forrest has published a great deal in this area. Here's a 2019 presentation of his titled "No Photon Left Behind: Challenges in OLED Outcoupling"
One method that I heard him talk about as far back as 2001 was a microlens array. Page 11 shows that Forrest had achieved external quantum efficiency of 60% or so at 1000 nits with a microlens array, more than a 2X improvement. LGD has used this tech in their TV panels.
So maybe that's part of the story. But we really need to know the full explanation behind the 72%. What is it? How much is UDC's IP and how much others? Can the UDC part lock out competitors? How much of that 72% can SummerSprout claim? We'll never know how secure our investment here is unless we know these things. |
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