LED's manufacturers huge effort to increase efficiency past of that alternative technologies now is ended. Once all main LED manufacturers have high power white LEDs achieving 150lm/W on operating conditions, we still continue seeing efficiency improvements, but gradual and progressive, until, luckily, reaching 250lm/W on 10 years. As higher the efficiency level, the smaller in percentage the new improvements.
Now the focus is on lowering manufacturing costs. Many are working on the migration to silicon substrate, which technology is very well developed for mass production, and allowing the use of larger wafers, a key to lowering costs. But LEDs grown on silicon have lower efficiency, at least for the moment. But if they cost 1/3 for 1000 lm, they finally will displace other more expensive technologies, despite an small lower efficiency.
For sure than a flashaholic prefer to pay 3x for best LED and get the best color quality, the longer runtime and easier thermal management. But LED manufacturers thinks on the big market, not on us.
So it is to expect a slower rate on efficiency improvement from now on, but prices dropping continuously for a given amount of lm. Once LEDs have the performance to compete effectively with other lighting alternatives, new manufacturers, especially asians, currently producing silicon semiconductors will join, production capacity will grow very fast and later prices with go down as consequence of effective competence, that until now has been relatively limited.
