Haitz's law

Haitz's law is an observation and forecast about the steady improvement, over many years, of light-emitting diodes (LEDs).

It is considered the LED counterpart to Moore's law, which states that the number of transistors in a given integrated circuit doubles every 18 to 24 months.

[1] Both laws rely on the process optimization of the production of semiconductor devices.

[3] Besides the forecast of exponential development of cost per lumen and amount of light per package, the publication also forecast that the luminous efficacy of LED-based lighting could reach 200 lm/W (lumen per watt) in 2020, crossing 100 lm/W in 2010.

The theoretical maximum for truncated blackbody white light source (at 5800K colour temperature with wavelengths restricted to the visible band of between 400nm and 700nm) is 251 lm/W.

Illustration of Haitz's law. Light output per LED package as a function of time, note the logarithmic scale on the vertical axis.