Looking for small,low power,high efficency leds

[croled]

Hi guys (sorry for my bad english),

I'm trying to find LED for a project I'm working on.
Desierd LED must be:
-small (actually light), smaller than 3mm led,
-high efficieny is very important (energy source will be very small NiMH battery)
-any color( I will decide later)
-narrow angle(<30 deg.) has advantage(is there some method to make a lens for 120 deg. smd leds-like plcc?)
-low cost(<1$)
-low power, because it will be running at 1-3 ma (high power leds have low efficiency at very low current,wright?)

So far I find some really nice osram leds:
LA N91E/LB N91E/LT N91E(6mg weight,3.5lm amber,3.9lm green,1.1lm blue@20ma,20 deg. angle)
http://catalog.osram-os.com/catalog...Oid=000000050001d40900fd0023&act=showBookmark

Nice is, that all Osram products have given candela and lumen values in datasheets,other manufacturer don't (difficult to compare).

Any suggestions?

 

[luckybucket]

That is one small led your after. I've never even heard of anything that small or I'd post some helpful information. I want something similar to put on my dogs collar but an xp-g is small enough for me. Good luck on your search.

 

[spencer]

I don't believe anything is made smaller than a 3mm LED that has a narrow viewing angle. I new Luxeon C is pretty small (don't remember if it is smaller than a 3mm) but it has a wide viewing angle.

 

[JohnR66]

You might try to use a 3mm LED given the availability, low cost and lens as part of the package. According to CPF member jtr1962's graphs, driving small LEDs at 3 to 5 ma will be in the peak efficiency range where current white LEDs make well over 100 lumens/per watt. going below 2 or 3 ma, the efficiency drops like a rock. I'm not sure about color LEDs though.