What I meant was that *Power* LEDs have barely improved in efficacy since 1960...I admit that *power* leds weren't really even availalable in 1960-1999.
I worked for an LED company, and the engineer told an invester that LEDs are getting 50% more efficient every year. This is not true. People (not those reading here) are quoting the improvement in *indicator* leds from 1960-1999, and that is irrelevant for leds for general lighting.
https://en.wikipedia.org/wiki/LED
..under the "Efficiency and...." section you can see that since power leds came of age in 1999, they have shown very little improvement in efficacy since them...Auger recombination has held them back.
In fact , over the last 6 years, LEDs have barely improved at all in efficacy.
From 1960 to 1999 the improvement in small indicator leds was very good, as you see in the wiki graph near section "The blue and white led". (Haitz law)
If you want to see how poorly efficienct leds still are, just take a look at the size of the heatsinks on cars with led headlights.....you wont find a picture of one on www as the manufacturers don't want people knowing they have to use heatsinks that are that enormous and complex in terms of multiple protrusions.
At another place, When we used to show our sales guys the internals of a led lamp (~3 to 8W) , they all bemoaned the size of the metal heatsink it contained, this always being their first observation...."does it really need that big chunk of metal in there?"