Broadband quantum dot micro-light-emitting diodes with parabolic sidewalls

Arrays of long wavelength, self-organized InGaAs quantum dot micron sized light-emitting diodes (mu-LEDs) with parabolic sidewalls are introduced. The parabolic profiles of the mu-LEDs produced by resist reflow and controlled dry etching improve the extraction efficiency from the LEDs by redirection of the light into the escape cone by reflection from the sidewalls. A fourfold increase in the substrate emitted power density compared to a reference planar LED is measured. The reflected light is verified to be azimuthally polarized. The spectral width of the emission can be greater than 200 nm. (C) 2008 American Institute of Physics.