Increasing output power of LEDs ($\lambda$ = 1.7–2.4 $\mu$m) by changing directions of reflected light fluxes in GaSb/GaInAsSb/GaAlAsSb heterostructures
Abstract:
It is demonstrated, using the example of light-emitting diodes (LEDs) based $n$-GaSb/$n$-GaIn-AsSb/$p$-GaAlAsSb heterostructures, that the formation of a curvilinear reflecting surface consisting of hemispherical etch pits on the rear side of an LED chip leads to an increase in the output radiation power by a factor of 1.9–2 in the entire wavelength interval studied ($\lambda$ = 1.7–2.4 $\mu$m) as compared to the LED chip design with a continuous absorbing ohmic contact. This increase in the LED efficiency is related to a change in the directions of reflected light fluxes upon reflection from the hemispherical etch pits.