The XLamp® XP-L2 LED is Cree’s highest performing high-density discrete LED. Leveraging key elements of Cree’s SC5 Technology™ Platform, the high-power XP-L2 LED improves the lumen density, voltage characteristics and reliability of the XP-L LED in the same 3.45mm x 3.45mm package. This best-in-class performance enables lighting manufacturers to deliver differentiated solutions at lower system costs for applications such as roadway, outdoor area, spot and high-bay lighting.
Uh, oh! This looks like what happened to the XP-G2: more output but no dedoming anymore, an ugly looking die when projected and major tint differences between spot and spil in a reflector light. Stock up your (easy dedomable) XP-L’s fellows before they are discontinued!
Definitely disappointing from the de-doming aspect, but I’m sure there will be an HI version eventually. I just hope the tint is better than XP-G3 so that they are useful domed. It will be the new leader in Max-lumens @ 90CRI.
Back when the XPG3 came out and we were trying see if the dedomed or sliced version had good performance, I was learning about the structure/architecture of LEDs better in order to understand the connection between dedoming and light recycling. See here for an explanation.
In this article , some details of different architectures are discussed. It mentions one strategy for increasing light extraction efficiency, light recycling, in which there is a reflecting silver layer below the LED junction. Photons that don’t escape the LED package are reflected down past the junction and reflect off of the silver layer, getting another chance at exiting the package. I think the luminance increase we see from dedoming has to do with this reflecting layer.
As we have noticed, there are some LEDs that don’t have bond wires on top. This is an architecture called “flip-chip”. Both the positive and negative contacts are on the bottom. My hypothesis is that the flip-chip style LEDs do not benefit nearly as much from dedoming as the traditional architecture with visible bond wires because of a difference or absence of the reflecting layer under the junction.
For example, the XP-G3, which is a flip chip style, did not have good performance when sliced or dedomed. The Nichia 219C which also is a flip chip style without visible bond wires also did not have good performance when sliced. The XM-L2, XP-L, and XP-G2 experience a ~1.9x increase in luminance upon dedoming, while the flip-chip style experience a ~1.3-1.5x increase. Another example is the third generation Oslon Square, which has visible bond wires. Although this LED is apparently difficult to dedome, user FmC has had some success, and the luminance increase is on par with the XPG2.
Well….we will test it for dedoming anyway, XPL wont be discontinued any time soon, and i am pretty sue there are more emitters to come from Cree, so dont give up hope
XPL HI can be dedomed too ( pretty easy though) and when they announce the XPL2 Hi version we will dedome it ( i hope easy again )
I tried a XPL HI dedome using ZEP Aerosolve II, after 18 mins all around the phosphor loosened up, but the shiny surface coating of the phosphor looked rock solid. On an older XM-L2, Aerosolve II popped the dome off in 12 minutes. This is my first time testing dedoming with this stuff, so dunno all the details (testing the LED, etc.), but it's a big time saver and lot less odor than gasoline.
I'll try it in a tuff LED, like a XP-G3 or XPL V6 0D to see how it does, but doesn't sound like it will work on them.
On the new XP-L2, reviewing the specs is somewhat disappointing - rated lumens is slightly less than XP-L specs at all bins, plus still listing "only" V6 as the max bin. Lower Vf is darn nice though, and "temperature coefficient of voltage" looks improved, which I think that means under heat, it will have less loss of voltage, therefore more output.