Comparison between blue lasers and light‐emitting diodes for future solid‐state lighting

Abstract

Solid‐state lighting (SSL) is now the most efficient source of high color quality white light ever created. Nevertheless, the blue InGaN light‐emitting diodes (LEDs) that are the light engine of SSL still have significant performance limitations. Foremost among these is the decrease in efficiency at high input current densities widely known as “efficiency droop.” Efficiency droop limits input power densities, contrary to the desire to produce more photons per unit LED chip area and to make SSL more affordable. Pending a solution to efficiency droop, an alternative device could be a blue laser diode (LD). LDs, operated in stimulated emission, can have high efficiencies at much higher input power densities than LEDs can. In this article, LEDs and LDs for future SSL are explored by comparing: their current state‐of‐the‐art input‐power‐density‐dependent power‐conversion efficiencies; potential improvements both in their peak power‐conversion efficiencies and in the input power densities at which those efficiencies peak; and their economics for practical SSL.

Broadband white light emission from Ce:AlN ceramics: High thermal conductivity down-converters for LED and laser-driven solid state lighting

“…Many researchers today feel that the future light engine for high powered lighting will move from LEDs to solid state lasers. 12 This is in response to the fact that LEDs face a so-called droop-lowered conversion efficiency-as input current density increases. By contrast lasers are not susceptible to droop and could provide significantly higher input powers leading to higher output light intensities.…”

Visible light communication using InGaN optical sources with AlInGaP nanomembrane down-converters

“…For example, InGaN-based white-light emitting diodes are replacing older light bulb technologies for home and street illuminations while InGaN laser diodes are used for optical data storage and are being considered for future ultra-efficient lighting [1]. An emerging application for InGaN-based white LEDs is visible light communications (VLC), which has been gathering a lot of attention recently [2,3].…”

High-speed indoor visible light communication system employing laser diodes and angle diversity receivers

“…Therefore, visible laser diodes (LDs) can be used as a main source of illumination instead of LEDs due to their high efficiency, especially in high power applications [9]. One of the main potential issues associated with using laser lighting is that lasers can be dangerous to human eyes.…”