Gigahertz modulation of tunneling-based GaAs light emitters

We demonstrate GaAs surface-emitting light-emitting diodes (LED's) containing a resonant tunneling structure that combine ultrahigh modulation bandwidths in excess of 2 GHz with high-external efficiency. In contrast to previously demonstrated resonant tunneling LED's that were used for quantum-well (QW) emission at cryogenic temperatures, these devices operate at room temperature (RT). These devices are less affected by nonradiative recombination compared to the conventional heavy-doping approach, in which a high-modulation bandwidth was obtained only at the expense of a more than proportional reduction in quantum efficiency.