Do low voltage 5W Luxeon exist?

[soloco]

I hear about really low voltage 1W Luxeons that can reach full brightness with like 2.5V. Does a similar 5W exist that can maybe be driven at 5V?

 

[FalconFX]

Well, if you can find some Vf 5Wers hanging around R or S Vfs... Those would be sweet to nearly direct-drive off of a 6V supply....